trialsguy
Silver Member
I have a onan 20hp gas engine and am wondering what the cyclinder compression should be? Hour meter states 600 hours but I bet its double that. reason for the question is that I am loosing oil and smoking through the ocv type vent on the dop of the engine, and am wonder if it is excessivie blow by or if it is a faulty valve. I have right at 85 psi on both cyclinders and that seems a little low to me, But it starts and runs great but now I have oil running out of vent and smoking up the place