yellow_cad

I tried to send you a PM but it said that your box was full.

Have a 72 OSSA MAR and looking for 7 or 8 inch high bars (7/8 inch OD) preferably in the USA but doesn't need to be.

Wow!! That fantastic little clip is a real education. Those guys were flying by today's standards. I'm 65, my bikes almost 40, I'm not trying to set the world on fire just have fun with a new interest. After watching that film, my first question is if you're an older guy with an older bike do you try to do trials the way they did when they designed the bike or do you use the older bike and the newer methods? It looks like two different animals. With my different motorcycles and cars, I am sort of a purest at heart but I don't know what would make sense for getting the most out of trials on a twin shock bike.

I believe the carb on my 72 OSSA is a Makuni (VM26) . Cleaned the carb completely and for the most part the bike runs pretty good with the exception of a sticking throttle and good idle some times not good other times. The throttle linkage isn't new but seems to work real well. Most of the time the linkage works freely and I can hear the slide shut but sometimes it gets stickty. Is it possible that my internal carb spring is too weak? Just in case it matters for some reason, I am not able to get the the adjusting screw that moves the slide to make much difference no matter where it is located. I seem to be setting the idle with the linkage fine adjust at the top of the carb and the fine adjust on the throttle linkage.

Right now I have a pretty much stock 72 MAR. It has what appears to be a stock four inch high bar and stock foot pegs. I am new to trials but I believe that I want to be slightly more erect. I have read it suggested to move the pegs down appx. three inches (weld plate to frame) for a lower center of gravity, but I have also been told that it is better to raise the handle bars instead and leave the peg height stock to maintain clearance to the side of the skid plate. Any suggestions whether to go up (raise handle bars), or down (lower pegs), or both would be appreciated. I do plan to modernize the pegs (wider and springs), but wanted to get the whole picture before going one way or the other on the improvements. Also would appreciate any recommendation as to height changes. Right now I'm not too sure if two inches is enough or three inches is too much. I am around six foot and pretty much average for that height. Is there any type of formula that I can use in getting at least a good static position?

Right now to shift into first with the clutch lever pulled, it sort of snaps into gear. Here are my questions: I read where it says that I should have 1/16 inch of play at the clutch lever on the case. I have 1/8 inch. Should I adjust this down to 1/16 inch? If so, how do I keep the clutch from turning while I loosen the clutch adjusting nut. Also, how much play should I have at the clutch lever? If I have the correct play at the lever on the case, is this the play that I should have at the hand lever? Also, my idle might be a little high. So, is my current 1/8 inch OK and I just need to get the idle down? Thanks for any help on this.

What is the best way to find and fit a spark arrestor on a vintage bike? Are there units that work with my existing muffler? I live in Northern California and have a 72 OSSA MAR.

The previous owners did a good job of wiping out the exhaust threads on the side of the cylinder. One previous owner had rigged the exhaust ring to be held on with four small springs that also attach to the cylinder fins. The ring is held in place but since there isn't much left of the threads, it does leak some exhaust gas. How bad is this for running since most of what I will be doing is slow speed? Are there any short term fixes and what is the best long term fix? Thanks for any help on this. Jim

I am new to trials. I have a 72 OSSA MAR. I live in California USA. Can the foot peg position and the foot pegs be changed for the vintage trials class I would be in with this bike? Thanks, Jim

Thanks Woody. My engine number looks like it starts with an M but all of the numbers on the charts start with B. Aside from that my number range is correct for a 72 MAR. I'm new to 2 strokes; how much smoke out of the exhaust is OK? Since it will run and I can warm it up, will a compression test tell me anything?

Thanks for the tips Brian. Just a few questions: What is a good source for the special tools? Does the clutch need to be removed if I am just replacing the crank seals? I have the Clymer book, Vintage Dirt Bikes (OSSA is one of three bikes covered). Is this the book you are referring to? I went to OSSA World but can't find any books. When you talk about the decompressor being used in place of the brakes, what exactly are you referring to? How would this work? Jim

I just acquired a 72 MAR that seems in pretty good shape. It does smoke a bit and drip some oil so I understand that I need to do the crank seals and gaskets. What special tools do I need to do this? Also any tips would be greatly appriciated. When it is all tight, what is best to run in the gear box? I have some Redline MTL. It was missing the decompressor but I found one NOS. Does the decompressor go in the hole at an angle to the ground? Thanks for any help on this. Jim in Folsom, CA