mcman56

My C15 has a clutch actuator (pivot) that threads into the timing cover. I have been told the Cub is the same. It interfaces with the cable and rod. When rotated into the correct location, the threads are not tight. Does this matter? Will it flex around an destroy the threads? Is there a standard correction? Is seems like the threads should bottom as the correct position is met.

On the subject of not fully warming the engine.....I grew up in an area with cold winters and in an era of cast iron V8 engines. The old engines took a while to warm up and one winter I had a job just a few miles away. If I only drove to work, the oil would absorb so much mositure that it would eventaully look like milk. A good long drive would dry it out.

If that bike is like the one I had, ignition and lights are run on AC. The factory regulator was missing when I got the bike. The aftermarket regulator I bought simply stops the voltage from going too high. One wire goes into the lighting circuit or to the battery connection if it is still there. The other goes to ground. There should be a direction or orientation so it will only work when the wires are hooked up correctly. (I don't know if there will be damage if it is hooked up the backwards.) Once the votlage gets up to about 14 VAC, it will bleed off to ground and the device will get warm. The regulator will keep the lights from burning out so fast.

What bike are the wheels from? The rear brake and sprocket are on teh same side.

I went at this from a different direction and machined a complete timing side bush from bronze. (The original steel was not very tight and I had seen sold bronze bushes for the bigger twins.) However, I found it a real challenge to install. I had to be careful to align the two flats to the cases during the install. However, careful meant slow and the bush would heat up and start to sieze in the bore. To a lesser extent, I had the same problem with the transmission bush that must align with the mall pin. Are there any secrets to this?

You are off by one decimal point. 1 mm = 0.03937

I have used carbide end mills in a milling machine to cut a groove in the inner race. Once the wall thickness is very thin, it will split with a little force. It was surprising how easy the races machine with carbide tools.

Interesting post but can some translate "shifter" into American?

This is not an answer but may be useful. After buying a used Reflex, I noticed that the front wheel was not centered in the forks. I forget how far off it was...maybe 1/4" plus. It looked like the original wheel (steel in the US) and had no signs of being altered. I had it relaced to center it but since that time have heard that some street bikes actually come with wheels that are not in line. Could it have been offset by design? Did he check the original wheel for centering?

I have had to drill my own pilot jets for the TLR200. If I remember correctly, the #40 is .4 mm or 0.0157". A 1/64 drill is 0.0156" and a #78 drill is 0.016". You can get small drill sets at: http://www.mcmaster.com/#31055a64/=npars I did once see a link for carb parts that suggested the #40 jet from some year CB750 would fit but never tried that one. The TLR200 main jets are the same as XR100 mains but the pilots are different.

I use a 1990 XR100 brake cable on a Reflex. It is a little shorter and gives a better feel.

What does your clutch work like with that set up?

I'm not certain but the spacer from a Reflex (86'/ 87' TLR200) should be the same. You could look at a parts blow up, like the one on bikebandit, to get an idea.

Does anyone have a sprocket recommendation on a C15 for Trials? I would prefer to stay away from a huge back sprocket and am really only concerned about getting first low enough. This bike has the 33/17 first gear....listed as wide ratio in the RR book. (Oddly the other gears match the close ratio numbers in the book.) From what I can tell, the smallest transmission sprocket is 13 tooth and the smallest motor sprocket is 18. With the existing 56 rear sprocket, I calculate an overall 1st gear about 24:1. The same calculation for my Reflex with 9/44 final drive gives me 45:1. Am I missing something?

I removed the small end bush from my C15 and the surface finish inside the rod is really rough. It looks like a very bad drilling job. As far as I can tell, it is pretty much round with an ID of .751/ .752. Is this rough surface normal or common? I'm thinking it needs to bored for an oversize bush but don't want to bother if this is actually normal.

I cut spacers from PVC pipe.

Opening up the pilot jet slightly will improve the idle. To stiffen the front fork, I cut off the tightly wound piece and then set preload to about 1". I only weigh 155 and this works for me. It does not coil bind.

What compression ratio should be targeted for a C15 intended for trials? It is a 1960 C15S. The available range seems to go from 6.5 to 10:1. It looks like early C15T had 6.5:1 and later models had 8:1.

I use the adaptors on a 2002 Sherco. They may not look as clean as a new top fork clamp but are hidden under a big pad anyway. They work well but add height to the bars. I used the Protaper adaptors. Factory Suzuki/ Ktm Protaper bars have a very low rise so the height ( and sweep) worked out to be the same as the Renthal trials bars that were on the bike. I like the fatbars because they are a little easier on the wrists and arms.

I happened to find a similar but wrong size bearing to look at. It is a NA6904. The outer race has an oil groove around the outside and one hole leading ti the needles. The inner race has no hole or grooves.

It looks like the crank journal is actually 25 mm. Does this mean I could just use one of their complete bearings with inner and outer race? Like their NKI-25/20 or NA-5905 (25 42 23)? The case would have to be machined to match the OD but it would avoid having to machine hardened parts. I guess it would still need thrust washers. Are they really needed for thrust or more to limit oil flow out the side of the bearing?

The picture on your blog explains quite a bit. I thought the needle bearing came with an outer race. I can do lathe and mill type machining but these inner and outer races must be hard so grinding would be required. Is the original steel outer piece of the bronze bush hard or is a whole new one required? Looking at the Rubert book, if you stick with a bushing, you should just replace the bronze piece. However, I have been looking on line and the bronze piece does not seem to be available separately.

That is an interesting idea. I pulled the specification on the needle bearing. On my engine, it looks like the oil pumps from the cases, through the bushing and into the crankshaft to feed the big end bearing. How do you get oil flow though the outer wall of the needle bearing? What material do you use for the thrust beraings?

I have had very good success with the cast aluminium brake pedal on a Beta. Bending "work hardens" aluminium and heating followed by slow cooling softens it. The trick is to find the right temperature for softening. I believe that is what the soap trick listed above does. (burn off temperature = softening temperature) I have used an acetelene torch in the same way. You can use a very "rich" torch setting to coat the aluminium with black soot. Then use a standard setting to burn the soot off. It would then be soft and ready for bending within reason. My Beta pedal was bent into a U shape so I used two or three heating then bending steps to get it back to straight. I have also heard you can coat with black magic marker and then burn off but I have not tried that.

Thanks for posting that Blog. It will be a real help. The pins were cut off or broken off screw threads. Someone must have put them in to prevent movement. The one in the distributor came out with an ez out but did not seem to do anything. The ez out broke off in the one in the cases. The big hammer method removed the distributor but did create a little damage. When I finally split the cases, it looked like there was dried mud in the crank area. Luckily the transmission and timing side parts look servicable. Does someone sell an engine bolt/ screw kit? Most of mine are in poor shape. I hear about converting from a bush on the timing side to a roller or needle bearing but do not see anything available on line. How is this done? Is it expensive?