Salty's Garage

Tachometer

2010-12-18T14:14:00.000-08:00

In an attempt to figure out the revs on Salty, I picked up a cheap little tachometer from Prohoists. It is self-powered, and pretty darn easy to install. The pickup signal wire wraps around the main coil lead, and ground wire mounts to a chassis ground. The end.

And it works. I've heard I might need to play with how many times the signal wire wraps around the coil wire, but so far it seems to work. It might reading a tad high, but I want to borrow the wireless tach from work to compare the two before getting it dialed in.

I built a quick little aluminum mount that attaches to the steering stem. I still need to pickup a couple small bolts to mount the unit to the bracket I built.

C'

Drilling Jets

2010-12-02T19:48:00.000-08:00

I decided to get myself setup to drill out the main jet on the Mikuni mounted on Salty. As it happens, I also have been dialing in the tuning on the same model of carb mounted on the 140cc chinese engine I have in my Trail 55 rat bike project.

I came across this fantastic page, which saved me the time and effort of converting the numbers and matching up the drill sizes:

http://www.affordablegokarts.com/Drilling%20Main%20Jets.php

As luck would have it, I had picked up a cheap drill bit set from Harbor Freight last month, just to fill in some gaps I had with other drill bit sets.

Salty's carb had a 95 main jet, and is acting as if it too lean. I've had to move the needle clip to the bottom most position to get it to pull at part throttle, yet it totally falls flat at wide open throttle. My spark plug is also too light in color after I did a few spark cuts.

Ratty's carb came with a 97.5 main jet, and has always acted very lean at part throttle application. Almost like a lean surge you would feel with a weber carb on a car when it was too lean.

So I made up a little aluminum block fixture to mount the main jet in, which fits nicely in my bench vise. I made a one jet size increase at a time (or as close as I can get) so I used a #60 drill bit for Salty, and a #59 for Ratty. The process was very easy and quick. I can remove the carb, take off the bottom half and have the main jet in my fixture in less than 5 minutes.

Unfortunately, I've had no daylight hours to run either bike since I drilled the jets. And the weather has started to turn a bit rainy this evening. Hopefully I can get out on the road this weekend and try to dial things in.

More Jetting Notes

2010-11-25T13:27:00.000-08:00

So...I was completely wrong in thinking I was running rich in the mid range. After adjusting the needle clip up two grooves (making it leaner), I went for a ride. It was terrible. It wouldn't take throttle at lower rpm, and would lose power at 3/4 throttle. I was able to clear it up by adding some choke, which adds fuel.

I rode home, and adjusted the needle clip to the lowest of the five groove positions, making it full rich. It responded instantly. It now runs great through the rpm range, even capable of pulling from a stop in 2nd gear. It is amazing how much of an effect such a small change can have.

As a reminder, here is the diagram of the needle clip arrangement:

The only issue I'm seeing now is I'm puking a bit of oil out both the main crankcase vent, and around the dipstick. Now I see why they made aftermarket breathers that screwed into the dip stick opening. I'll have to scan ebay for such a device.

Mikuni Carb Adjustments

2010-11-24T14:51:00.001-08:00

I've been tinkering with the jetting on Salty the past couple days, and have had a couple old Honda enthusiasts show interest in how this larger 24mm Mikuni will work on a small 50cc Honda. I'm curious too, and have only begun to start messing with things.

First, I wanted to link everyone to this page: http://www.iwt.com.au/mikunicarb.htm

This is a fantastic primer on how a typical Mikuni motorcycle carb functions.

The first two times I've run Salty, it was very boggy at lower rpm. This was compounded by the fact I have it geared very tall, using a 16-tooth front sprocket, a stock 40-tooth rear sprocket, and the taller 2.75"x17" rear tire. I'm also running a 1/4-turn throttle mechanism, which reacts much quicker than a typical slide throttle.

Pulling away from a stop wasn't easy. It would bog very badly unless I gave it a little Fred Flinstone action to get rolling. It also ran very poorly at low rpm in second gear, when trying to pull away from slower turns.

So I started by adjusting the pilot circuit, as this has the biggest effect on low speed, and low throttle opening running. Usually this screw is set at 1.5 to 2 turns out from all the way in. In my case, it was set at 1.5 turns out. After getting the bike warmed up, and with a decent idle, you simply turn the adjustment screw in or out, and you'll be able to hear/feel a change in idle speed. In my case, it was rather dramatic, as turning the screw out (making it leaner) raised the rpm quite a bit. If you go too far, the rpm will start to lower. So you get a feel for where to set it based on rpm. In my case, I settled on 2.5 turns out. I then adjusted the idle speed back to where I wanted it.

It immediately improved throttle response. Even with the bike just sitting in neutral at an idle, it was very boggy before. Now it just revs clean with no hesitation. I then went for a short ride. It was dramatically improved, especially pulling away from slow turns in 2nd gear at lower rpm.

I now need to turn my attention to full throttle use, as it isn't quite right. I have a feeling I'm quite rich overall, especially since I needed to lean it out so much even at small throttle openings. When I'm cruising at mid to upper rpm in second gear, it pulls very nicely as I open the throttle. But I notice the last 10-15% of the throttle opening makes zero difference to acceleration. If anything, it feels like it stumbles a bit. A check of the plug indicates it is running rich. Going from 3/4 to full throttle opening is right in the transition range between the needle and main jet circuits.

I don't have any spare main jets, so I'll need to order some. In the meantime, I thought I would play with the needle jet position (1/4 to 3/4 throttle mixture) by adjusting the needle clip position leaner. I'm currently set in the middle of 5 clip positions. so I'll move it up a clip and see what that feels like.

If it isn't too cold tomorrow, I might go for a short ride.

Brake Light and Another Ride

2010-11-22T17:23:00.000-08:00

I wanted to throw a brake light on Salty, so I could run him on the street. I never really thought about that when I made the seat/cowl though, so I needed a simple solution. Thanks to my previous experience doing a taillight for my rat bike project this spring, I decided to use a simple 9V battery as the power source. This way I don't have to tap into the lighting coil and worry about the rectifier with the stock wiring loom.

The end result is a 9V battery, a 9V battery holder, some wire, a stock rear brake light switch, and a pair of 1/2" push-in red lights. All the components are housed in the left side pod cover, and runs through the seat in plastic tubing to avoid and chaffing on the fiberglass. The lights simply push through a 1/2" hole I drilled in the bottom edge of the seat cowl, as shown below:

The lights are actually quite bright when viewed from behind.

After completing that task, I took another ride around the north part of town. I've learned a few things riding it:

-I need to move the pegs a couple inches lower, or a couple inches further back, or a combination of the two. I'm just too cramped.

-Having the bike geared so tall means that 2nd gear isn't that usable for putting around city streets. 1st is too short, 2nd is too long, especially for slower speed corners. I think I'm going to throw a smaller front sprocket on the bike, which luckily doesn't take much time.

-This bike is fun! It doesn't have the scoot of the rat bike, but being all hunched over and close to the ground makes it exciting, even at 40mph.

C'

Kickstand and Number

2010-11-21T17:13:00.000-08:00

I finally got off my duff today around 1pm, and did a bit of work to Salty. Job one was to make up a kickstand, to replace the center stand. Centerstands are great for performing maintenance, but they are difficult to work around. Usually the exhaust, chain, and rear brake levers all have to be positioned just right to avoid interfering with the centerstand.

In my case, the only thing that interfered was the rear brake lever. I had built it with the centerstand down, not realizing it would swing up against the brake lever with the bike on its wheels. The easiest solution was to just take the damn thing off! I can still slide it under the bike if I want to use it for maintenance, but I built up a simple little kickstand for day-to-day use.

I had found a $7 kickstand made for a kiddy bicycle at Wally World a few week ago, which I installed on the Trials bike. As luck would have it, the K-Mart just down the street had the exact same unit. I bolted it right under the motor (where the stock footpegs normally bolt) and shortened it a tad to be the correct length. I topped it off by welding on a washer to give it a bit more contact area with the ground.

Job number two was to finally put some class letters/numbers on the number plates I had built many moons ago. In this case, M-PG 50. Modified chassis, Pushrod Gas, 50cc.

C'

Chain Cover

2010-11-20T16:16:00.000-08:00

I spent a little time in the garage today working on Salty. It is about 45-degrees out, rainy and windy, but luckily the garage is warm! I raised the front ride height about 1/2", as I found the front shocks wanted to just barely bottom-out on small bumps. That wasn't difficult, just fiddly.

The other thing I did was take on old chain cover from the parts bin, clean it up, fit it, and paint it. These early Hondas had a fully enclosed chain cover to keep the oil from flinging off the chain and onto the bike, and keep dirt/grunge from getting onto the chain. Usually these covers are ditched the first time the chain is adjusted or replaced.

The cover is in two pieces, a top and bottom. Each piece bolts to the swingarm, and then they fit into each other for a tight fit.

C'

Riding Salty for the First Time!

2010-11-19T11:36:00.000-08:00

After many months of little issues, combined with the fact I built up another complete bike (the Trials bike) I finally got back to Salty the past couple days. I had it running, but not very well many months ago. It was running very strangely, and sporadically. Sometimes it would kick over first try, other times I would wear my leg out trying to kick it over. If I got it running, I could never get it to hold an idle without needing the choke fueling circuit on, which of course raised the revs up high enough. So basically, I've been troubleshooting little issues and not having a lot of luck isolating the main problem. It wasn't fun dealing with the same problems everytime I turned my attention to it, so I moved on to other projects.

Yesterday I decided to take off the complete carb/manifold/fuel line and do a thorough cleaning. I drained the tank and didn't see any sediment. I built up a new fuel line with a small fuel filter, which it didn't have before. I also disassembled the carb and gave it a douche, even though it looked spotless inside. I put everything back on, and it fired up fairly easily. It still hunted a lot while trying to fast idle. Then, as I was glancing down at the ground, I hurt it sputter and I saw a little puff of moisture shoot out around the base of the intake manifold I had built. It kept sputtering, and shooting out. It was obvious there was a little crack in the intake manifold where I had welded it together. For a refresher, here is the manifold I built:

The "left" side of the manifold is where it bolts to the cylinder head. It is a very tight fit between the pipe and the nuts that secure it, so I had to file away a bit of meat. I also apparently didn't do a fantastic job welding it in that area, as the crack formed right there.

Guess what? I did a shitty job welding two intake manifolds. I had built a test manifold before this one, to get all my angles and dimensions correct. So I grabbed it out of the bin, and bolted everything back up. Salty fired on the first kick, and ran great for about 2 minutes, holding a perfect idle and taking throttle. Then I heard it stumble and saw a puff from the same exact location! What the hell. I think I'm just cracking what little weld is there as I tighten the nuts to secure it to the head. Two manifolds down. But at least I maybe found my mystery problem?

Instead of trying to fix both manifolds, or make a new one, I thought of some better solutions. One of which uses a stock C110 intake manifold, which I happen to now own three of. The two C110 parts bikes I grabbed from Ashland for $50 each had one. The problem is, this manifold is designed to use a small section of rubber hose that clamps to a round section of the stock C110 carb. The Mikuni I'm using has a bolt-on flange. So I have a few options. I can make up a new flange and have it welded to the stock C110 item. Which may be the best long term solution. I don't weld aluminum, however, so I'll need to find someone to do that for me though. I'll likely have two built.

The short term solution was to hack off the carb side of one of the manifolds I built. This side has a much wider hole spacing for the two mounting bolts, so I have a very good welded connection there. I then connected this piece to the stock c110 intake with a piece of 7/8" ID fuel hose I had. It is a very snug fit, and with a few ugly hose clamps it fits and feels secure.

It worked too, as the bike fired right up, held an idle, and even held a nice low rpm idle with no choke after it warmed up. It takes throttle well too. So of course, I grabbed my helmet and realized I was going to actually ride Salty for the first time. I was never able to get it running well enough to want to try.

So I did. I blasted up and down the road a few times, going through all the gears. It actually runs on the road now! I was very excited. It wants to bog a bit right off idle, but if I'm smooth with the throttle and give it a quick paddle or two to get it rolling, I can accelerate off. The engine in the bike is a 3-spd auto clutch, with a large front sprocket. So first gear is a bit tall, and I think the 1/4-turn throttle I have on it is a just a bit too quick reacting. I'm sure I'll get a bit smoother as I ride it more.

So there you have it, Salty not only seems to run, but it goes down the road. It isn't the most comfortable bike in the world, but it is actually doable on the road. I just fold up my long legs, hunch over, and go for it. I'm going to fiddle with a few more things this afternoon, and hopefully take him around the block more before the rain comes this weekend.

C'

Proof it Runs

2010-07-03T15:30:00.000-07:00

After a few minutes of tinkering, I got Salty to kick over easier, rev a bit cleaner, and eventually idle fairly smoothly. Here is me tinkering:

And proof it runs! I'm thinking of renaming him Smokey, as he tends to smoke a little. Probably a bit of blow by the freshly honed cylinder and new rings. And I think I squirted quite a bit of magic oil in the cylinder last year so as not to turn it over dry.

I still need to build a shift lever and adjust the auto-clutch before I can see if it motivates down the road under its own power. But at least it manages to run and idle better.

C'

De-Gunked Engine and Freshly Sealed Side Cover

2010-07-02T21:11:00.000-07:00

I whipped off the side cover on Salty's engine, and gave it a good thorough douching inside and out. There was about half a gasket stuck to the case, so that took some scraping and wire brushing to get it off. I also cleaned up the mating surface on the engine, and gave the entire area a good spray cleaning and brushing.

It was much cleaner that I thought it would be, as witnessed by the photos below:

I used some permatex gasket sealer on the mating surface and installed the side cover. I pulled out my trusty in-lb torque wrench and carefully went around the bolts a few times until everything was snug.

I figure I'll wait till morning to fill it with oil, and then get back to running it a little and dialing in the idle and mixture settings.

C'

It Runs!

2010-07-01T21:39:00.000-07:00

After work tonight, I started playing in the garage. I had several small fixes in mind for Salty, but didn't think I would be trying to get him up and running. Somehow, things just came together, and the end result is a running engine!

Fix number one was to modify the center stand return spring plate. When I built the rear brake arm, I apparently fit everything with the bike sitting up on its center stand. Unfortunately, when I lowered it down on both wheels, the little "C" shaped bracket that attaches to the frame and the return spring interfered against the brake arm. A little grinding, drilling a new upper locating hole, and some fiddling, and I got everything to work together.

Then I installed the spark plug and fit a kick start lever from some random bike with just enough "curve" in its shape to clear the exhaust. After that, I decided to put a small amount of fuel in the tank to see if the rebuilt petcock I had mounted worked and held fuel. After a few minutes of no drips, I then decided to fill the crankcase with oil.

I gave it a few slow kicks to get the oil circulated and noticed a few small leaks around the "passenger" side case. Then it hit me, that I never made a gasket for that side case. I had simply fit it on loosely when mocking up the exhaust. It didn't leak bad, but had enough drips to where I'll need to pull it off and make a gasket. Or I'll just use some gasket sealer snot.

So, I had a carb getting fuel, a spark plug getting spark, and a bottom end with oil. Well hot damn, I guess I better take it outside and see if it starts.

As a reminder, the engine in Salty right now is sort of a Frankenstein. It is an old ass Cub 50 bottom end, with the 3-speed auto clutch. And by old ass, I mean it came out of a parts bike and had a thick oozy goop coating the insides. I "washed" out the innards and soaked it in the solvent tank for a few days at work. It turns over, but other than that, I have no idea how the bearings and trans looks.

Then I mounted fresh top ends parts, which are the main hot rod items on the motor. In this case, I'm using one of the two freshly honed standard bore cylinders that I had 0.040" milled off the top of the barrel. Combined with the ported C110 aluminum cylinder head that has a matching 0.040" milled off the bottom mating surface, that raises the compression from 9:1 to around 12:1. I also fit stock sized lightened valves, lightened rocker arms, and used, but nicely cleaned up stock piston with new rings. Like I said, a Frankenstein engine I figured would be perfect for just using to mount up in the chassis and build stuff around. If it wants to actually run, then that would be cool too. So my expectations were pretty low at this point.

A big part of getting Salty up to record speeds will be the gearing. Last year, I spent a lot of time making a spreadsheet to determine speed in gear for both the C100 3-speed trans and C110 4-speed trans. I've long since forgotten the outcome, but I think both the 3-spd and 4-spd have similar top gears ratios, so if I could get up to speed using the semi-auto 3-spd, then I didn't have to worry about mounting up and building a clutch cable.

So, short story made super long, Salty runs. It took a while to kick over because I realized my throttle cable adjustment was too "tight" so the throttle barrel was lifted a little in the carb. Essentially, it was as if I was holding open the throttle. After solving that, I gave it a little choke and it fired right up, and revved to about 90,000rpm. It was probably only 4,000rpm, but god damn was it loud! I fiddled with the choke a little, and adjusted the idle screw until it sort of settled down. It wasn't running real great, and wouldn't hold an idle, so it eventually died.

Then a few minutes later Susan got home, so I started it up for her. And of course it ran better, so I assume a little bit of heat and a few more adjustments to the idle and mixture screw, and it almost settled into a normal idle. It even revved fairly clean through its range a few times.

I immediately grabbed the oil drain pan and pulled the drain plug to drop the oil, since I'll need to seal up that out case cover. And of course Susan got a photo of my triumphant moment:

It still isn't quite road worthy yet. Obviously I need to fix the leaky side cover, put oil back in it, get it to run a bit better and hold an idle. Besides that, I need to fit a chain, do a full nut and bolt job on the entire bike to make sure nothing rattles off, and then do it again to make sure i haven't forgotten anything. Maybe this weekend I'll get to ride him down the street.

C'

Throttle Cable and Fuel Lines

2010-06-27T17:11:00.000-07:00

I've actually done a few little things on Salty over the past couple weeks, but nothing exciting enough to really report on its own. I had rebuilt the stock petcock and mounted it, got the intake manifold mounted, and ran some fuel lines.

Since it was 100-degrees outside this afternoon, I thought the living room would make a great garage space, so that I could build and mount a throttle cable. Luckily, Susan didn't mind as she was busy surfing the vast internets for dinner recipes:

I had this 1/4-turn throttle assembly in the spares box, and I modified a C100 throttle cable to fit:

With the help of Tom Cruise I got it all wrapped up:

I'm getting real close to seeing if this thing fires up.just a few more minor details to take care of.

C'

Sparky McSparky!

2010-03-24T18:36:00.000-07:00

After a bit of fiddling with various stators and coils, I finally got some spark to the plug. Apparently I have about four different stator assemblies, two different ignition coils, and a random selection of harnesses. What I had in the bike was a mixture of I don't know what, and it wasn't working.

So I grabbed the stator off the original C110 engine and cleaned it up. It really didn't take much effort, as I just ran some emery through the points, lubed the little foam pad, and blew the crud out with some compressed air. After I installed it, I mounted the stock C110 coil and ran a few wires. I don't plan on running any lights on Salty, so I didn't use the stock harness or key assembly.

I found this wiring diagram online here:

I isolated the ignition circuit and just a ran a simple on/off toggle switch up to the headstock area. The switch is grounded, so that turning it "on" releases it from ground, and the magic sparks happen.

I was pretty excited to see the sparkplug spark. So much so, I called my pops right away, since he was over last night doing some troubleshooting with me.

C'

Front Number Plate

2010-02-28T18:46:00.000-08:00

I've actually been fiddling with Salty a bit the past week, but don't have much to show for it. One of the items I did manage to complete was a front number plate. Which is pretty much a piece of plastic cut to shape. I'm not exactly sure why it took several days to put together this little item, but it did!

At least Salty has had some company, since Ratty has been hanging out next to him.

C'

Dirty Magneto is Dirty

2010-02-23T19:14:00.000-08:00

I pulled the flywheel off a couple days ago, so I could get into the general flywheel/magneto area and do some cleaning. I took about half a pound of grunge off the inside of the flywheel, and began the dis-assembly and cleaning of the stator assembly.

The entire stator assembly comes off with a couple machine screws, and this is what I found:

Since I have a few extra engines, I grabbed a spare stator assembly that was in much better shape. I've already R&R'd the contact points, and will finish cleaning up the rest of the assembly tomorrow.

The "fresher" assembly:

C'

Flywheel Puller

2010-02-22T19:25:00.000-08:00

I realized I had no way to pull a flywheel off the C100/105/110 engine, so instead of trying to fab up some puller, I hit the easy button and ordered one via the internets. After some quick searching, I came across a unit that apparently fits about 1 million other types of bikes. I picked it up from Heartland Products.

The big threaded boss threads into the flywheel, and the smaller section gets turned up against the end of the crankshaft. A couple gentle turns, and the flywheel popped right off. Be sure to keep track of the tiny woodruff key.

Chris H.

Salty, Front & Center

2010-02-17T20:32:00.001-08:00

A few things got arranged tonight, so Salty has some room to work.

Long Time No Salty

2010-02-16T13:12:00.000-08:00

It has been well over a year since I've blogged about Salty. Unfortunately, that also means I haven't touched the bike for a year either. It is sitting comfortably in the garage between the Bridgestone Sport 90 and the Hodaka ACE 90. Looking lonely.

Over the previous winter, I decided to build a new race motor for the Formula Vee. This was something new for me, so I took my time on it. I had the engine in the car running, about a week away from my first race date, when a rod bearing decided he wasn't happy. I pretty much pouted for a week, then pulled the engine out and tore it down. It was very obvious what had happened. I then spent the next couple months building up the engine again, this time with success.

I built an engine stand to run the engine on before putting it in the car. It ran great. Luckily, it also ran great in the car. I've made two race days with it, which also meant a bit of fine tuning to the cooling system (scoops and oil coolers) and a few other odds and ends. Before I knew it, it was winter again. I haven't touched the race car for several months, nor have I touched any bikes.

But that will change. My race club is lacking local events early in the year, so I've decided to jump back on Salty over the summer. I don't know if I'll actually get to Bonneville though. I would need to make that a primary objective, schedule vacation, set other projects aside etc. Initially, I just want to get it running and finish him.

I'm also going to finish a few other bikes. The Bridgestone needs a few small touches, I have a Yamaha YG-1T that needs some details too. Basically, I'm going to pull all the bikes out of the garage, walk around them and make a list. If it isn't raining this weekend, I may do that Saturday. I'll also organize the garage and make a real work center for Salty.

So keep posted, as I hope to have more stuff to blog about over the next few months.

Chris H.

More Tires, and Red Wheels

2008-11-22T18:30:00.000-08:00

I've been busy working on my Formula Vee race car, and haven't given Salty much attention lately. Well, that changed this weekend. I received two more of my back-ordered tires (only one more rear tire remains) and set about getting them mounted up.

Installing a new front tire on the chrome front wheel rim, in the living room, while Susan watches Dancing with the Stars.

Last month, I had assembled a second set of wheels, using an older pair of wheel rims whose chrome was not in fantastic condition. I decided to paint the rims red, to match the tank and seat. I wasn't sure if I would like the end product on the bike, but figured what the heck!

Installing a rim band on the red wheel rim, before the front tire gets wedged on:

A note about installing tires. I don't have any fancy tire installation tools, so instead I use a pair of old screwdrivers that I've smoothed over on the end and edges, and a couple paint can opening thingies. You know those little guys that looks like a bottle opener, but have a small lip for getting paint can lids open. I also use some warm soapy water, and take my time. After a few tires, I've gotten pretty good at it.

And here is the half finished product, with a red wheel on the front:

I also had to make a new exhaust bracket, as the right side cover of the C100 3-speed engine has a little "bump-out" for the automatic clutch. Luckily I had more than enough room to move the exhaust out a tick to clear.

After I get the new engine built for the FV, I hope to get Salty up and running. Possibly over the long Christmas weekend.

C'

Test Engine Assembly and Mockup

2008-10-26T18:26:00.001-07:00

I had a little time this afternoon (after a nice birthday lunch) to assemble the "test engine." This engine uses the 3-speed auto clutch from a C100, but with a higher compression C110 piston and the bigger port aluminum C110 cylinder head. The cylinder barrel and rocker box assembly are shared between the C100 and C110.

Right side of C100 Test Engine

Left side of C100 Test Engine

And of course I couldn't wait to get it mocked-up in the frame, to check the fit of the exhaust and intake manifold/carb setup. As it turns out, the "right" side engine case is slightly different between the C110 and C100. The C100 has an extra buldge on the clutch side because of the automatic clutch mechanism. This buldge hits the exhaust pipe I built. Just enough so that the exhaust won't bolt on the swingarm bracket. I have a couple options, the easiest being to extend the exhaust bracket, but I'm fearful that might make it look funny if it starts to "run down hill" as it exits the back of the bike. I'll need to spend some more time fiddling with it. Hhhmm.

Test engine installed, intake and exhaust mocked up on bike for fitment

Little Salty is really starting to look like a bike now

Another productive and fun day in the garage.

C'

Silver Side Covers

2008-10-25T18:57:00.000-07:00

After a bit of photoshop work, I decided I liked having the side covers painted silver. So...I painted them silver yesterday. Exciting I know!

Silver side covers. The end.

After some work porting formula Vee cylinder heads, I'll get back on Salty. I should have one of my cylinder barrels back from the machinist, and will assemble the "test" engine.

C'

Front Fender Fun

2008-10-20T18:34:00.000-07:00

All it takes is a little paint, and suddenly little Salty starts to look like a motorcycle. I prepped and painted the front fender over the weekend, and got it mounted up late last night. I just couldn't wait to see what it looked like.

It took a bit of fiddling to get the fender to fit just right, as it isn't the original C110 front fender. I'm not actually sure what it came off of, as it was just sitting in my spare parts bin. It looks the part and will keep salt spray off the engine when bombing along at 50mph.

Freshly painted front fender mounted on bike:

Close up of the front fender, still needing a good rubbing out and polishing:

Lastly, I test fit the side covers. The "left" side covers up the battery, while the "right" side covers up the air filter. I'm not yet decided on the final cover. I shot them black primer just to see how black would look, but I don't like it. Perhaps silver will work for them. hhmm.........

C'

New (and cleaned up) Engine Parts

2008-10-18T19:35:00.000-07:00

I spent some time today cleaning up engine parts, mostly top end cylinder head parts like rocker arms, valves, springs, pushrods etc. I also took the opportunity to lighten a couple sets of just about every component. My goal is to have two complete running engines, and enough spare parts to rebuild each engine if needed.

I'm building up the original C110 4-speed along with a C100 3-speed. The C110 will have all the hot rod light weight parts, while the C100 will get mostly stock parts, and end up being the test mule over the winter and spring.

Two sets of lightened rocker arms:

A few sets of valves. The back set is stock, the front three sets have been backcut and lightened around the tulip:

One of two sets of brand new 40mm C10 Piston Kits I found, complete with pin, rings, and pin clips:

10-Pack of "O-Rings" kits. Seal the cylinder head to cylinder barrel, around the pushrod openings:

After I assemble a rocker box and cylinder head, I'll assemble the C100 engine and get it mounted in the frame.

C'

Garage Organization

2008-10-06T19:49:00.001-07:00

This falls under the "not really Salty related" but at least I'm better organized category.

My Pops gave me the red chest of drawers on the left, the bottom section. So I moved my bottom chest to underneath the work bench to house those small odds and ends that always get lost. I also added a bunch of small shelves underneath the center bench to store typical power tools like drills, grinders, and torque wrenches. I had a bunch of wasted space before this. Not really all that pretty, but at least I can find most of my tools now!

C'

Building an Intake Manifold

2008-10-06T19:31:00.000-07:00

After getting the Monster Carb in the mail on Friday, I set about building an intake manifold for it. I had sketched up various ideas, and settled on a system design I was hoping I could build at home, without needing to outsource all the fun work.

The concept uses two large washers, one for the flange that connects to the cylinder head, and one for the flange connecting to the carb, connected with a section of curved pipe massaged to fit the proper openings of the head and carb. With washers and pipe in hand (and a cold beer for refreshment,) I got busy.

Washer on left fits cylinder head, washer on right fits to carb. Note that carb mounting holes are slightly off centered "up and down" in relation to the center hole:

Center pipe section is cut from a conduit sweep. I cut four little "pie sections" out of the cylinder head end so the pipe could be made slightly smaller in diameter to fit smaller intake port opening:

Small end of pipe was formed, welded, and ground smooth:

Freshly welded intake, ready for high heat resistant paint, followed by a good wrapping of exhaust header wrap for better thermal properties:

Carb mounted on intake. Intake bolts are threaded into the flange, which was tapped before painting:

Overall, this was a fun project to work on, and is sized to work with several typical small Mikuni carbs, which all have slightly different flange bolt patterns. I also made a second set of flanges, and have enough of the conduit sweep remaining to build a second complete manifold.

C'

Sneak Peak!

2008-10-04T17:42:00.000-07:00

Just a quick sneak peak of the bike as it is getting assembled into chassis form. The paint is a little dull and dusty, since it hasn't been rubbed out yet.

Monster Carb

2008-10-04T17:32:00.000-07:00

A small package arrived on the front porch this afternoon, while we were off picking up key project items (book shelf, salad bowls, and new shoe baskets) from Ikea. It contained a brand spankin' new Mikuni VM24. That's right, 24mm, or about the size of my big toe.

Compared with the 16mm carb that came on the C110, and the 13mm carb that comes on the C100, this VM24 is indeed a monster.

VM24 uses a 48mm bolt spacing "hot side" flange

A simple hose connection will be used on the inlet side

I've already mocked-up an intake manifold to get the positioning of the carb correct, in relation to the engine and intake connection on the frame. The net step is to actually fabricate the flanges for both ends, and create the center pipe, which will be both tapered and bent in a 70-degree smooth arc.

C'

A Little Bit of Paint

2008-09-28T18:38:00.000-07:00

I got busy priming and painting the past couple of weekends. Last weekend, I worked on the gas tank and seat, which got sprayed bright red. This weekend, I added some silver to the main frame, front fork, rear swingarm, and a few small brackets and accessory items.

A few items painted

The last big item that needs paint will be the front fender, which needs a bit more body work to get it ready for silver paint. And of course the side covers, and some more brackets etc. I guess I better make a list!

Just for fun, here's another photo of the rear tire, a IRC NR53, as mounted on a back wheel.

I also spent some time today mocking up an intake manifold. In fact, my mock-up may end up being my final product. After I clean it up and lay on some heat resistant paint, I'll snap a picture.

C'

Front Sprockets

2008-09-24T12:25:00.000-07:00

As mentioned in the last post, I need to "gear up" the bike in order to see speeds over 52mph, the rating of the bike at 10,000rpm with stock tire and gearing. The slightly taller rear tire will help a little, but I knew I would need to make changes to the sprockets. In stock fashion, the bike uses a 14T front sprocket and a 40T rear sprocket, giving it a final drive of 2.85:1.

I began searching for bigger front sprockets, but found it difficult to find items marked for use on the C100/110 engine. Most sprockets are tagged for XR50s, or CT70s etc. I got lucky the other day and found a Honda Passport (C70) site that gave a listing of other Honda models that used the same sprockets. It included the C100, along with a dozen other small Hondas like the CL70, XR80, ATC70, S65 etc.

So, I started searching for sprockets for some of these other Honda models. I came across Beatrice Cycles ( http://dratv.com/index.html ) which happens to have an excellent breakdown of parts, categorized by model and major component. If you want electrical parts for your ATC110, they've got it. Likewise suspension parts for your Z50.

I searched around the C70 page, and found that they offered 15T, 16T, and 17T front sprockets. I bought one of each, along with a few extra tire tubes (for the red wheels.) Everything arrived at my door within 3 days. I quickly ran out to the garage and confirmed that yes, these sprockets do fit the early pushrod motors.

From L to R: 14T, 15T, 16T, 17T

Based on my gearing calculation spreadsheet, these sprockets should give me a range of speed from 55 to 67mph in 4th gear at 10,000rpm. I plan on building up both the C110 4-speed engine, as well as a 3-speed C100 engine, which has a slightly shorter top gear.

Perhaps I'm spending too much time worried about this one subject, but given the fact Bonneville is at much higher elevation, I wanted to have plenty of options for fiddling with gearing. A few hundred rpm could make a difference, especially when your only dealing with 5.5 to 6hp!

C'

Assembled Wheels, Chopped Tail, and New Tires

2008-09-22T21:28:00.000-07:00

Over the past few weeks, I've ordered an assortment of parts for Salty, ranging from NOS Piston kits, to larger front sprockets, to a couple sets of tires. This post will focus on the tires, and their fitment to the bike.

One of the "speed modifications" to this little bike is to gear it up. In stock form, the bike runs a 14-tooth front sprocket, and a 40-tooth rear sprocket, with a 2.25"x17" rear tire. Based on some calculations I've put together, this should put the top speed around 52-53mph at 10,000rpm. Perhaps I'm hugely over estimating the performance of the bike, but I wanted gearing options that would let me run at least 60mph.

One of the easiest solutions is to run a taller rear tire. That isn't a simple matter when it comes to small bike tires, however. I want to keep the tires fairly narrow too, so after much research I found the Michelin Gazelle M62 tire. This is a small motorcycle/moped tire that is speed rated to 82mph. It is available in several sizes, including a 2.25x17 (front) and a 3x17 (rear.)

However...nobody had any of these tires in stock. I talked to several vendors, and ended up having orders sitting around for more than 2 full months, with expected delivery dates getting pushed out further as each week passed by.

So, I researched more and came across the IRC NR53. It is a semi-slick treaded tire, again made for small motorcycles and mopeds. It too is speed rated, and offered in both a 2.25x17 and 2.75x17 size. I placed my order and within days I received one of four tires. I ordered two fronts and two rears. The other three tires are on back order, but hopefully might actually get shipped sometime this year!

I quickly mounted up the 2.75x17 rear tire to the rear wheel assembly I had put together. I'll call these the "chrome wheels" since I'm using a set of stock wheel rims with pretty decent chrome. I knew there could be some clearance issues under the rear fender with this wider rear tire, so I chucked it under the bike to see how bad it would be.

As it happens, I also took an opportunity to trim the rear fender. As the rules state, there can be no rear fender extending past the centerline of the rear wheel, but the seat can essentially act as the rear fender, which mine will. Sorta. The exact rules reads as:

...
5.F. FRONT AND REAR FENDERS
Front and rear fenders may be removed. Generic, replacement type
fenders may be substituted. Rear fenders may not extend beyond
the centerline of the front or rear axle. Elongated seat may act as
rear fender and is subject to scrutineering.
...

So, I grabbed the cutting wheel and shortened the rear fender. Don't worry, lovers of originality, as I have several stock rear fenders sitting on the shelf from parts bikes ready to go on should I ever want to take it back to the original full-fendered look.

Rear tire mounted up, and rear fender shortened per rules:

As it sits, I barely rub when I'm fully loaded on the bike, at its lowest settings. It is barely rubbing on the edges of the tire. With just a little "spreading" of the rear fender - what's left of it - I should be able to go off-roading without rubbing.

In preparation for the other set of tires arriving, I put together a second full set of wheel assemblies this past weekend. We'll call these the "red wheels" since I painted them red to match up with the red tank and seat (more on that later.)

Second set of wheel assemblies, sittin' pretty waiting for fresh tires

Tommorow, I'll post about my newly found set of front sprockets.

C'

Leathers!

2008-09-12T14:41:00.000-07:00

One thing I needed to find before any running with this bike, was a set of suitable leathers, boots, and gloves. Per the rules, and general "rule of thumb for Bonneville," I looked for all leather construction, without much perforations across the front and in other critical areas. This seems to be the key, as many track day leathers use perforated material across the chest, and under the arms for ventilation. I didn't really need to pickup anything quite this soon, but I've been keeping an eye out for items locally.

As it turns out, I came across a set that seem to fit the bill, for a good price. They are a two-piece set of Sinsalo leathers, full leather construction, dual zippers at the waist, that fit me well. A tad snug in the legs/knees, but I am comfortable while in the tucked position. They also came with a set of full leather boots and gloves, both of which fit perfectly.

Captain America Returns!

Fully Tucked and Ready for Speed

All I need now is a suitably rated Helmet. My SA2005 Helmet I use for the Formula Vee is not M rated, and has a much smaller field of vision. So the search begins for a M2005 helmet...

C'

Building an Exhaust

2008-09-02T08:46:00.000-07:00

One of the items I still needed to build was an exhaust system. Per the rules, the exhaust couldn't extend past the rear tire, and it's opening couldn't be directed at the rider, or the salt surface. Unlike 2-strokers, you don't have to design an expansion chamber to produce power at a certain RPM for a 4-stroke. However, there are still some basic calculations that can be run to optimize length and diameter, based on RPM. Also, stepped designs can be taken advantage of.

These calculations called out for a main header pipe roughly 18-inches in length, and a diameter matching that of the stock header pipe. So I grabbed a spare header pipe, added a few inches to it, and came up with my 18-inches exhaust length. Unfortunately, this ended the exhaust just ahead of my foot, and looked rather incomplete.

So taking advantage of a stepped design, I used a piece of larger diameter pipe to bring the exhaust back behind my foot, then built a simple megaphone that attached to the end. The megaphone was rather fun to build, as I simply cut out a pie shape wedge from a piece of 2 inch pipe, then shaped the leftover piece into the cone shape, welding along the seam.

In the end, I'm left with a main header pipe to match up with my RPM zone, that is stepped up and mated to a megaphone for looks. a simple hanger is attached to the front swingarm bolt. The entire thing will get coated in trusty bbq paint, and possibly wrapped in header wrap. A few photos are shown below.

Proportions fit the profile of the bike pretty well

The header pipe actually runs inside the "stepped-up" section of pipe about 6 inches, for a total primary length of 18 inches.

Megaphone was "squashed" to produce an oval section. I might give the tip a slight slash cut.

Chris H.

Front Fender Fun

2008-08-21T10:49:00.000-07:00

After sorting through my bins of random spare front fenders I've pulled off parts bikes, I came across a scabbed up unit off a 1965 Suzuki K11. It has the same full fendered lines of the original C110 fender - which didn't come with the bike - and the same basic proportions. After a bit of measuring, and test fitting, it looked like it would be a good match up.

I only had to drill two new holes for it to mount to the front fork tubes, and shorten the little rear stays that support the back of the fender. It will obviously need a bit of body work, as it was rather dented and skinned up, but I like the overall look of it.

Suzuki K11 front fender mounted up easily, allowing for full suspension travel with no rubbing.

Easily mounts to upper front shock bolts

Should help keep the salt spray down

Chris H.

Making a Seat and Gas Tank Extender

2008-08-18T12:46:00.000-07:00

One of the keys to building this bike was to keep it somewhat "period correct" with regards to modifications. I was hoping to build it like it would be built back in the 60s. One of the main items I knew that would need to be built or modified would be the gas tank and seat. The seat would obviously need to be made to accommodate my skinny butt when tucked down in my Bonneville speed demon posture. That means there is a huge gap between the seat and tank.

Option 1 is to buy a reproduction tank like on all the vintage road race bikes. Something like the tank on a CR110 Honda immediately comes to mind. Besides the fact a reproduction tank like that costs more than the entire bike did, I didn't entirely like the look of it. Well, I loved the look of the long skinny tank, but it just didn't fit in with the hot rod theme I was going for. Besides, the stock tank was decent, as were the chrome panels and rubber knee pads. Option 2 is to build a tank extension. Basically, a fake extension that would fill up the gap, but also be strong enough to support me laying my belly and chest on it, and support the grip from my knees as I squeeze down on it when tucked.

I decided to go with option 2.

Having made a similar rear seat section for the Bridgestone 90 Racer project, I had an idea of the generic size and proportions.

Photo of the Bridgestone rear seat section for reference:

I started off with a cardboard template, to get an idea how big the final product would need to be. I then got to cutting and grinding and drilling and welding, and made up a very simple frame that mounts to the bike using the rear gas tank hold down bolt, and the upper rear shocks mounts for support. It is basically a 1" angle iron craddle that the tank extension/seat will then bolt to, and then be able to be removed as one piece.

With dimensions in hand, I visited the local craft store for some crafters foam. These foam blocks are available in various sizes, and as it turns out these little brick shaped pieces matched up with the width and height I was looking for.

Using a scrap piece of wood, I glued and screwed the foam blocks to each other, then to the wood in a rough shape. I then proceeded to carve and sand the foam into the shape I was looking for. It had a little bit of taper from bottom to top, and I made the rear portion of the seat have the usual cafe' racer bubble shape.

Foam bricks carved and sanded to shape:

After the foam mold was shaped to satisfaction, I got out the fiberglass and resin. I precut about 4 layers worth of cloth, using both 8 oz bi-directional weave and some thicker chop mat for added thickness. It was a fairly warm day, so I had to mix the resin in smaller batches and work quick. I wouldn't say it was the best job I've ever done, but I knew it would require a lot of finish work anyways to make it smooth and pretty.

After it setup, i popped the mold off the wood, and removed the bottom layer of foam bricks. This was the underside of the part, which would get mounted to the angle iron base. I then added a few more layers of fiberglass to essentially create a honeycomb of fiberglass and foam. The main section of the tank extension, and the rear tail bubble are completly filled with foam, and surrounded by fiberglass. the result is a very strong and stable part that can support some weight.

I then trimmed the part using some basic angle grinders and thick sheet metal sheers. I gave the bottom edge a little shape to match up with the rubber knee pad on the stock gas tank, while keeping the bottom edge just tall enough to completely hide the angle iron frame work underneath. After a bit of final grinding and fitting, I mounted the seat to the frame work, and then mounted it to the bike.

Raw fiberglass part on bike for test fitting

I let the part setup for a couple weeks before I started to do some finish body work to it. Using some good 'ol fashion body filler, I was able to clean up the surface. Luckily I still had my body filler scrapers in the toolbox, since the easiest time to do rough finishing on filler is right after it starts to setup, as it can be scraped off like a cheese grater, in little shavings.

Filler is a pain in the butt to sand, so anything to minimize sanding is worth it

It still needs some finish work in a few sections, but you can see the overall look of the tank extension and seat as it is mounted on the bike. I cut out a piece of 1/2" thick foam rubber for the cushion, which will just be spray glued down to the seat pan, with four small holes to access the bolts that secure the seat to the frame work underneath.

Here is a shot with the intrepid rider on board showing off his not-so-legal slippers and boxer shorts:

I'm still contemplating the next project, but I'm thinking it might be a small front fender to help keep the salt spray off the engine, bike, and rider.

Chris H.

Fun with Scales

2008-08-17T13:34:00.000-07:00

In preparation for the engine build, I picked up a US Balance Magnum 1000XR digital scale, so I could weigh all the little parts and have a baseline. The scale has a max capacity of 1,000 grams, with 0.1g precision.

After cleaning up all the parts, I weighed everything in the top end of the motor.

Engine Parts	weight (grams)

Piston	80.1
Piston pin	20.9
rocker arm shaft	12.8
small rocker arm	28
big rocker arm	34.7
rocker arm shaft spring	1
top piston ring	2.6
middle piston ring	2.6
bottom piston ring	3.1
short pushrod	15
long pushrod	15.7
intake valve	15.8
exhaust valve	17.9
inner valve spring	6.3
outer valve spring	15.8
keepers (pair)	0.8
retainer	4.7

I intend to build up a couple different engines for this project. I figure one will be a mild hot rod setup, with some basic lightening of components, increased compressions, bigger carb etc. Then a high test hot rod motor to eeck out that last 0.5 to 1hp.

Chris H.

Footpegs, Brake Lever, and Rear Shocks

2008-08-17T09:47:00.000-07:00

With the front handlebars in place, I was able to stretch out on the bike and get an idea of where I wanted to mount the rear foot pegs and rear brake lever. I figured fitting my lanky 6-foot tall frame on this bike could be a challenge, so I wanted to see how uncomfortable I would be using the stock passenger foot peg locations. As it turned out, it felt great. It gave me a good tuck, just enough clearance between my legs for the tank extension, and my feet/ankles didn't feel too cramped up.

Getting an idea where to mount the rear footpegs.

With the footpeg location selected, I then turned my attention to the rear brake lever. I had given thought to using a cable, but decided that an easier solution would be to simply modify the stock brake pullrod, and of course make a new lever. As it turns out, there is a boss mounted to the backside of the swingarm that locates the front of the rear brake/hub stay. So I got crafty and built a new lever

Simple lever cut from single sheet to minimize joints. 1/4" rod was welded to backside of plate to add stiffness. Entire lever pivots on the swingarm boss, pulling the shortened brake pullrod in a forward motion, just like stock.

As mounted on the bike, mostly hidden behind the swingarm.

I then scrounged through the spare parts bins and found a set of matching footpegs off a C100 that threaded right into the stock swingarm posts. The toe kicker for the brake lever is a passenger footpeg off another parts bike.

Brake lever, footpegs and toe kicker fitted.

Lastly, I decided to work up a set of rear shocks, as I was tired of having to carry the back of the bike around when I wanted to move it in the garage. I had taken dimensions of the little front shocks used in the leading link setup, and decided to see if could be used on the rear. The benfits would include having the same shocks on all "four corners" and since it is a nice little coilover setup, I could change spring rates or heights to best suit the bike.

Set of stock C110/100 front leading link shocks used in the rear. Like the front setup, I have about 1-inch of bum travel with my weight on the bike, with lots of adjustability should I want to change it.

Chris H.

Handlebars

2008-08-17T09:24:00.000-07:00

After I got the ride height about where I wanted it, I then started working on the handlebars. As a reminder, here are the rules specific to handlebar location for the class:

...
2.G. HAND/ FOOT CONTROLS
Hand controls (clutch and brake) must have a minimum 1/2” ball
on the end. Flattening of the ball end is acceptable, however all
edges must be rounded. All control ends must be an integral part of the lever. Foot operated controls must pivot independently. Foot throttle
must have toe clip with return throttle. All controls are subject to
scrutinizing. Riders in the riding position must have 10” between
thumbs. All handlebars must extend outside the fork tubes at a
minimum of 6” (streamliners excluded). Riders may be asked to
demonstrate their ability to navigate with the current controls.
Stops to steering must limit riders hands from touching the fairing
or tank at full right or left turns. A hydraulic dampener cannot act
as a fork stop.

and from the Modifed Frame opening paragraph

The lowest part of seat and handlebar grips must not exceed
an imaginary line drawn between the tops of the rims.
...

So, the bars have to extend at least 6-inches wider than the fork tubes, and there must be 10-inches between the thumbs when gripping the controls. And the position of the hands have to be higher than the top of wheel rim when viewed from side.

I quickly realized that I wanted to mount the bar much lower and farther ahead than could be accomplished using the stock handlebar clamps, to allow a much more stretched out seating position. As it happens there are several bolt locations on the front forks that would be suitable for mounting a plate too, which could then have a set of standard fork clamps. This was my solution:

Steel plate cut out to fit into the open space between the front fork tubes, bolted solid with 5 bolts. The handlebar clamps came off a Honda S90 parts bike, as did the 7/8" diameter handlebar.

I cut about 4-inches out of the center of the bar, then cut about 4-inches off each end. I'm left with roughly 11-inches between thumbs, while the bar extends a tad more than 7-inches past the fork tubes. And yes, there is clearance between the top of the tire and the steel plate at full compression of the front suspension.

Next up will be foot pegs and rear brake lever.

Chris H.

Mock-Up Begins

2008-08-16T16:48:00.000-07:00

After a weekend of cleaning, sanding, blasting, and priming, I decided to start the mock-up process for the bike. I set the frame up on a small stand, then fit the front and rear suspensions. My first task was to try and determine the ride height of the bike with me on it. My goal is to get it as low as possible to help minimize the frontal area, while still retaining enough room for my lanky features.

The first step was to take apart the front leading link suspension, and see if can be easily lowered. As luck would have it, yes it can. The small coilover shock setup inside the front forks uses a short coil spring mounted above a spacer roughly 2 inches tall. Simply taking out the spacer, or shortening it, will allow the leading link to move upward with weight on the bike. After a bit of measuring, I decided to trim the spacers in half. This lowers the front end about 2 inches total (based on the motion ratio of the leading link pivot) while still giving about 1 inch of bump travel.

For the rear, I initially threw on the hub/wheel setup with a spare 3x17 knobby tire than came off a spare bike in the parts collection. I wanted to check the clearance in the rear fender, since I assume I'll be running a bigger than stock rear tire to help gear the bike up.

Bike at its first mock-up stance

I even sat on the gloves to play Ricky Racer while the neighbors watched

My next project is to figure out where to mount the handlebars based on the very specific rules for the class.

Chris H.

Engine Details and Teardown

2008-08-16T10:06:00.001-07:00

A few Friday nights, I got the bug and decided to disassemble the top end of the motor. I have been curious as to the construction of the top end, and in fact, wanted to take some measurements and weights of the various pieces. Here are a few photos I snapped as the top end came apart, then a few details of the individual items.

Rocker box bolts and valve clearance caps removed.

Rocker box removed, looking at the top of the cylinder head.

Inside of rocker box, showing tiny rocker arms.

Cylinder head removed. Note the three O-Rings, two are 10.5mm and one is 7.5mm in diameter according to the manual.

Bottom of cylinder head. Note recesses for the O-Rings, and the copper head gasket tucked down inside the combustion chamber bowl. This aluminum head has considerably more fin area than the cast iron head from the C100.

Cylinder barrel removed, showing the piston hanging on the rod.

Bottom side of cylinder barrel.

Yes...that's a quarter sitting at the bottom of the photo, below the piston. Piston pin to its right, and the two massive pushrods on the far right.

More Photo Details

2008-08-16T09:53:00.000-07:00

I thought I would throw up a few more photos of the C110, in the as purchased state.

Side View of the engine. Note the aluminum head of the C110, and side draft carb, which differs from the C100's cast iron head and down draft carb.

Close up showing the rocker box assembly. Note the oil feed lines.

Close up of the HUGE 16mm carburetor.

Front hub detail. Note the leading link front fork arrangement, just like the C100.

Rear hub/sprocket setup. This bike came with an aftermarket aluminum sprocket, in the stock 40T size.

Them's the Rules

2008-08-15T16:19:00.001-07:00

Like any good builder, I sat down and read the rules. Twice. Then I re-read them and made notes on the items that I thought needed a bit of emphasis in the grey matter. In fact, I even setup a spiral notebook with a page (or two) dedicated to several key areas of the build. Knowing I would be a rookie, I didn’t want to make too many rookie mistakes. I figure if I attempt to follow the letter of the rule, I’ll have less grief. Yes, following the letter can be slower than following the “intent” and running into some grey areas, but again, I’m not wanting to get yelled at by the chief Tech Inspector. I’m hoping to use this notebook as a source for drawings during the build, and will ultimately send a packet of information off to the Chief Tech Inspector to get “buy off” of the many little items that need to get built.

Some of the parts I’ll be building, and rules I’ll be building too are listed below. It isn’t a complete list of rules, more just a sample of the specific parameters I need to keep in mind when construction begins. So in no particular order, and cut and pasted from the AMA Supplemental Regulations, for the BUB Motorcycle Speed Trials:

2.D. FUEL SHUTOFF AND ENGINE KILL SWITCH
Motorcycles must be equipped with a positive ignition off switch
to terminate engine power. The riders must be able to use the
switch without their hands leaving the handlebars.
Gasoline class motorcycles must have a fuel shut off, activated
from the riders position.

Meaning: I need ignition and fuel shutoff switches…

2.G. HAND/ FOOT CONTROLS
Hand controls (clutch and brake) must have a minimum 1/2” ball
on the end. Flattening of the ball end is acceptable, however all
edges must be rounded. All control ends must be an integral part of
the lever. Foot operated controls must pivot independently. Foot throttle
must have toe clip with return throttle. All controls are subject to
scrutinizing. Riders in the riding position must have 10” between
thumbs. All handlebars must extend outside the fork tubes at a
minimum of 6” (streamliners excluded). Riders may be asked to
demonstrate their ability to navigate with the current controls.
Stops to steering must limit riders hands from touching the fairing
or tank at full right or left turns. A hydraulic dampener cannot act
as a fork stop.

Meaning: Custom handlebars may be built, but must have 10” between thumbs, and at least 6” of bar extending out past the fork tube.

2.M. SAFETY WIRING
Transmission oil drain plug, and engine oil drain plug must be
safety wired. Axle nuts must be secured with safety wire or castle
nut and cotter key. Locking compounds are prohibited.

Meaning: wire and key important bolts/nuts

2.N. STEERING DAMPER
Required in all classes.

Meaning: gotta run a steering damper!

2.Q. TIRES
It is recommended that tires are rated for the appropriate speeds
and, use is at the sole discretion of the owner/participant. The rider
has the sole responsibility of inspecting the condition of the tire
before and after each run.

Meaning: I never even thought about speed rating for tires on a 50-60mph bike, but it makes sense. I’ll have to research brands and sizes.

MODIFIED FRAME CLASS
This section is designed to advance the efficiency of motorcycles
attempting records and increase the strength and stability. Overall
construction of the modified frame must be based on the original
production design and geometry and not purpose built.
Acceptable alterations include modifications of steering head angle
and removal of miscellaneous brackets and braces.
Half of the original cross structure members must be retained from
the transmission forward to insure structural integrity. Modified
frame class may be subject to special scrutineering of structure
welds. The lowest part of seat and handlebar grips must not exceed
an imaginary line drawn between the tops of the rims.

Meaning: Modify a stock frame to go faster. I thought it was interesting the seat and handlebar rule was thrown in this general section, as it seems like it could get lost. It basically says the handlebars can’t be below the top of the front wheel rim.

5.A. AXLES AND WHEELS
The minimum, non-stock wheel replacement size is 15”. Front and
rear axle material must be of Titanium or steel alloy only.

Meaning: no super small wheels/tires to reduce drag.

5.B. BRAKES
Rear brakes (required) must be actuated from the handlebars or
foot peg position. Front brakes are not required in this class.
Hydraulic Drum/ shoe and disc brakes assemblies are acceptable.

Meaning: no front brake required, but since it specifically says “Hydraulic” how does that affect the stock mechanical rear drum?

5.E. FOOT PEGS
Foot pegs must be a minimum of 6” ahead of rear axle.

Meaning: Foot pegs can’t be located way out in Superman land. As it turns out, the passenger foot peg location is 6.5” forward of the rear axle centerline.

5.F. FRONT AND REAR FENDERS
Front and rear fenders may be removed. Generic, replacement type
fenders may be substituted. Rear fenders may not extend beyond
the centerline of the front or rear axle. Elongated seat may act as
rear fender and is subject to scrutineering.

Meaning: I can run a different front fender that isn’t as bulky. In fact, I can run without, but it’s obvious a front fender will help to reduce the amount of salt thrown on the bike. Also, if I wanted to chop the rear sheet metal fender off, I could build a new seat to act like a fender.

5.H. GASOLINE TANK
Aftermarket gas tank is permitted with a minimum capacity of 1.32
gallons, mounted in the original position.

Meaning: I had to read this twice. If I replace the stock gas tank, the aftermarket unit must be 1.32 gallon in volume. However, the stock tank is quite that size, so perhaps I’ll use the stock tank in the build…

5.J. OPEN CLASS
Open class motorcycles do not permit streamlining. Streamlining is
anything forward of the rider that has the perceptible purpose of
directing, controlling or limiting the airflow around the motorcycle
and/or rider.

Meaning: No fancy fairing, or air diverters in the open class. If I want to throw on some fairings, I can run in Partial Streamlining class.

So, as you can see, it isn’t just a matter of throwing the bike together and driving to Wendover, Utah. I want to make sure the custom bits I build follow the rules, at the same time take advantage of the speed enhancing tricks. This should be fun!

Chris H.

Craigslist Comes Through

2008-08-15T15:29:00.000-07:00

One of the benefits of living on Northern California seems to be an extensive supply of small displacement Japanese motorcycles. In fact, all but one of my current bikes came off craigslist, and usually within a couple hours drive. Well, as chance should have it, a Honda C110 popped up locally a couple weeks after making my decision to run in Modified Frame 50cc Pushrod engine class. I contacted the owner, arranged for payment and pickup. In fact, a co-worker was heading down to the area the very next day, so he was kind enough to pick up the bike and deliver it to my door. So far this was proving pretty damn easy!

The bike was as described, which was mostly complete, rough around the edges, and full of $400 worth of charm. It also came with a box full of spare parts. The engine kicked over, and in fact had spark after I quickly swapped a spare battery in it. I didn’t attempt to start it, as I knew the gas – if there was any – was no doubt like varnish. It had some crusty bits, many of which wouldn’t be used on the final product anyways. So, my next step was to take a few dozen photos of the bike in the before state. Here are but a few to get your juices flowing:

Don't get too close:

It might bite:

49cc of Pushrod Thunder:

As you can see, this project will be as much about “restoring/rebuilding” as it will be about modifying the bike for racing. In fact, this is where I set a rather interesting ground rule for the build: I wanted to build this bike like it could have been built back in the 1960s. Meaning, I want it to have the feel of an old school hot rod bike. I’m not going to drop $600 dollars on a brand new café racer gas tank, or machine up billet rear sets, and replace every bolt and nut with titanium. In the end, I’m hoping it will look like a period built Café’ Racer Hot Rod. If this means the bike ends up 1mph slower, so be it. I can always break my rule the following year.

Chris H.

The Land Speed Bug...It Bit Me

2008-08-15T14:43:00.000-07:00

Sometime last year, during the build of our 1964 Bridgestone 90 Racer project, I got to thinking about Bonneville, and wondered if there were classes for small displacement bikes like we tend to ride and collect. After a little searching online, I came across www.landracing.com which appears to the best source of information for land speed events. It is a great technical resource, with links to all the different LSR clubs that run throughout the country. Being new to this world, I immediately downloaded just about every rule book and record list I could find online, and of course enjoyed the countless photo albums.

It took a bit of research and note taking to make it through the various rule books and record lists, because the classification system for motorcycles uses a lot of letter and number designations. Some of which make perfect sense, others that do not. And not all the LSR Clubs and governing bodies use the same rules and class designations, so that can lead to some confusion. In fact, I'm still a little confused about how this bike will cross-over into other clubs. And that brings me to the club/organization I have decided to run with. Long story short, I have Chosen the BUB Speed Trials group for several reasons, one of which simply comes down to the fact I’m a Nervous Nelly when it comes to new events, and it appears that the motorcycle only BUB group will have an event more geared to my rookie tastes. It was also nice that they have their rules available online, and have a great group of people willing to answer questions.

Now, what about the class and bike? Well, my original intent was to look at the various 50cc engine classes and make a decision on what type of frame I wanted to build. I actually wanted to build something, as in create something, so the Production frame class was thrown out. That left me with Modified Frame and Special Construction, as I wasn’t interested in building a streamliner. I had originally intended to go Special Construction, as it gives a builder a lot of freedom to design a bike. Perhaps too much freedom for a rookie builder though. So in the back of my head I had settled on a Modified Frame class, which as the name suggests, requires the use of a stock production frame, but allows all sorts modifications to things like engine, suspension, seating position, controls etc. In fact the rules are quite a bit more open than how I’m building my bike, which will be explained later.

In terms of 50cc engines, it was obvious that most of the classes have been dominated by late model water cooled 2-strokers, like the Aprilia RS50s that currently hold half a dozen records. For a while, this put me off, because building up a bike with a modern 2-stroke engine doesn’t even remotely fit in with my hobby of restoring 1960s Japanese bikes. Until I saw the engine class specific to pushrod engines. Yes, that’s right, Land Speed Race clubs still cater to the crusty old pushrod. Having a restored Honda C100 in the collection, I immediately remembered that these early engines were pushrod operated, and that Honda even offered a hot rod version of the venerable Cub, called the C110 Sport. I didn’t have one of these in the collection, but it has been on my list for some time. So perhaps I’ve come about this all wrong, or perhaps it will work as planned, but I chose a Modified Frame 50cc Pushrod engine class simply because I’ve wanted to build a Honda C110. Genius.

As for the existing records, it appears that a C110 in fact currently holds the record in both Gas and Fuel (Alcohol) categories in the Modified Frame class. There is no record set for Modified Frame Partial Streamlining (same frame class, but you can run some limited fairing and aero work to speed things up ) so perhaps if I feel frisky I’ll enter two classes, with and without fairings.

So there you have it. I’ve chosen a Club to run with, a Class to build to, and a Bike to build. Only problem was, I didn’t have a C110. The search began…

Chris H.