Yamaha 760 compression values

Hey guys, just looking at getting another waveblaster 2 and did a compression test on it.

Both cylinders put out 125 psi!

Is this two low or what should i be expecting?

Cheers

Paul

Hi. Was that done with a warm engine and throttle wide open

Hey ya.

Done with cold engine and both plugs out and earthed but no throttle open?

also good charge on battery so cranked over well

How much of a difference does this make having throttle closed?

Hi. If your engine is hot and the throttle is at full noise the difference can be alot more. Give it ago and let use no what the differance is.

O.K so throtle at full noise makes the compression rise to 144psi on a cold engine.

even psi on both cylinders! the ski is now behind my car. done! Booom! cheers

i have herd that is abot rite but i my self have never had them this low.allway been 140+ cold on closed throttle.and iv never done 760 allway been 701.

also it depends on your compression gauge....different brands and models can so show a big range of difference...

i think they normally around 140-150psi with stock compression.

also...note that the 760's have staggered compression (and staggered jetting in the carbs).
cant remember which (front or rear) has higher compression........

About 5 psi higher on the front cylinder