Tri Moto 125 hard to start, 115lb compression

[atc4everbob]

Hey guys, I posted a thread yesterday concerning a Tri Moto 125 very hard to start. About every 3 pulls it backfires bad. I was told it could be low compression. I did a compression test today on it and got a solid, consistent 115lbs. I do not know the compression specs - can't find any. Anybody here know what the numbers should be? I don't want to do a top end unless it needs it. Again, I'd appreciate some numbers from you wheeler heads. I checked for intake leaks and found none. What's there to check as far as timing on a 2 stroker? I've always had 4 strokers. I can be reached at bob_litzinger@hill-rom.com Thanks again. ATC4EverBob.

[Yamaha Tri-Moto]

I checked my manual and it says the compression (For the 175) should be 128psi with a min of 114. So dosent look like you have to do a top end rebuild.

[Unclediezel]

Weak spark?????---Do you have the correct plug in it?--

I would ask about the reed valves , but if it runs ok after "DRAG-STARTING IT" , Probably not a valve issue.

[Dan Tenn]

My 175 is a cold blooded SOB also. I take off the rear fenders, than put my hand over the intake to completely cover it. It usually fires right up.

[atc4everbob]

Thanks for the replies, folks. It's generating an awesome blue spark - lights up the whole electrode. Also, I went to a Yamaha dealer *Edited**Edited* posting these threads and told him I needed a plug for this bike (I did not tell him the plug # for fear it did have the wrong plug in it). He gave me a new one identical to the old #, I think a BP6ES. In regards to holding your hand over the intake on your 175 to richen up a cold start, that's interesting because I can pull mine while choked 10-15 times, pull the plug out, and it's barely wet. Seems to me it should be pretty saturated after that many pulls. I'll try that trick and tweak the mixture screw some more... If anyone else has additional ideas, I'm all ears. Thank you all for the valuable input.