87 Johnny 50 Compresion spec?

[thehermit]

I Have 90 (cold) on both cyl and am still trying to get to start. What is this engine comp supposed to be?

 

[Pony]

Re: 87 Johnny 50 Compresion spec?

Thats ideally a little low, would be better if it was somewhere in the 100's 120 to 140 would be perfect............BUT...........its even. It could simply be some carbon build-up and sticky rings. (could even be the gauge) When you get it going you could do a decarb and see if that brings it back up.

I don't think it is the reason you can't start it though, as it should run fine on the compression.

 

[JB]

Re: 87 Johnny 50 Compresion spec?

There is no spec except that the cylinders compress within 15% of each other, Hermit. 90psi cold is fine.

Go to the Engine FAQs to solve your starting problem..

Good luck.

 

[thehermit]

Re: 87 Johnny 50 Compresion spec?

Thanks JB-Pony. I have help on another thread on the ignition system troubleshoot.
TH