85' Trimoto 125 - Only can push start

[maestro7879]

I can only start the Trimoto by push starting it. Once warmed up and running it runs great with the choke off, but even after warm it still won't start with the pull start.

Compression - ~90psi
Carb Cleaned
Oil Injection connected and working well

Is my compression to low to start from the pull start ?
I also looked at the spark and to me it doesn't look that strong.

I have searched for what the compression should be and have read that it should be around 115psi.

I have 90psi which is a compression ratio of 6.12:1.
The specs from this site say it should be 6.4:1 and that works out to be 94.08psi. So that tells me I'm not that far off unless my calculations are incorrect.

[Yamaha_Rules69]

It definatly sounds like the compression is low. It should have over 100 psi. Maybe it just needs a light hone and rings, and you will have it running tip top. A friend of mine had the same problem with his 175 with low compression. It started when you pulled it behind another machine, but not with the recoil. He rode it like that for a while, and eventually the piston got scored on the exhaust side.

[old-yellow]

My guess would be weak spark or bad crankshaft seals but that's just my opinion.

[Russell 350X]

Sounds like low compression to me. New piston, rings, and a good hone will fix that. Easy to do on one of them.

[maestro7879]

Pull starter was backwards.
Starts on the first pull now.

[old-yellow]

Thats funny, I am glad you got it running.

check this thread.
http://www.3wheelerworldforums.com/showthread.php?t=86220