johnez

Hi I have tested compression on a Johnson 185 hp, 1985, it was between 70-80 psi is that very bad or it is normal for a engine who is 18 years old?
If it is very low how do I fix it?

Regards Jonas from Sweden

Ted G

iTrader: (1)

If the test was done with a warm motor, throttle blocked open, and a good battery cranking, then those numbers are too low. You need at least 100 psi, 120-130 is better. You will need to re-ring to bring the numbers up.

Al Oakley

to low 90 psi. is about the limit not worth tunning after that.needs rebuild . i would look for a good used newer moter perfurabley a looper.