1976 xr75 will not start! help!

Hello All,


I have this 76 xr75 that i just can not get running. If you have any info or advice please tell :goofy: . So when i got the bike it would turn over when i kick it and every once in a while it would start but run very badly and stahl out within seconds i adjusted the carb and nothing would change it. To this date i have done a top end re build. New piston, rings, gasket, cylinder was honed and looked great. After this compression is 90 dry. Does this sound good? it was around 30 before and i found one of the rings broken and thought maybe this would fix it. Put the bike back together and recleaned the carb ultrasoniclly again and same issue. I have set the points and assured it is opening and closing at the appropriate time. My spark is good when i remove and ground to frame. What am i missing? I was thinking maybe converting it to CDI but before i dove into too much research on the topic i thought i would see what anyone here would have to say.




Edited by npshurricane


Ok .. You say you have compression and spark .. What about fuel flow ?

Fuel flow is good. Tank has been flushed and A new inline filter has been installed. New points have also been installed and the gap has been set.

Im really thinking that this is an issue with the advance timing. Am i correct in saying that if i switch over to CDI that the new system will no long use the old advance timing? or am i wrong here? http://www.amazon.com/Honda-Performance-Coil-RACE-XR100/dp/B00KXDMRQE would this part be good? i was told by someone on here a year or so ago that i should use the CDI off of a crf80. 



so once again ive probably burnt 2 million calories messing with the bike trying to kick start it. Every 50 kicks or so it will give me a sign of life but never actualy continue to run. Im playing with the two mixture screws an choke trying all sorts of combinations and still no luck. i also ultra sonic cleaned the carb again and ensure all passages are clear. The fuel flow nice into the carb. Took the flywheel to a shop around here and they said the advanced timing lobe looks to be in good shape. Points and conensor are brand new. My key that holds he flywheel in place was worn down pretty bad and i was not sure if maybe it was slipping. Replaced that aswell same story. What else could be the problem with this? as for switching the thing to CDI im completely lost on the part i would need to purchase. A year or more back someone was saying i should get one from a cfr 80 but when i search im not finding anything. Anyone out there with some advice or a link to the correct part to switch this to CDI? Thanks

I have also re adjusted the valves to .02. On a long shot i am going to remove the advanced timing lobe on the inside of the flywheel and and turn it 180. 

at this point, I would make sure all the carburetor jets are clean and the float is adjusted to make sure that the gas is getting into the jets. I would also check the muffler and pipe to make sure it isn't clogged or blocked up.

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