compression test

[absosecur]

on a 71 50 hp merc i have checked the compression and on 3 of the cyl it is 120 and on the 4th it is 110.the manual says a difference of up to 15 lbs is ok.my question is this,is 110 to 120 lbs considered good compression??

 

[achris]

Re: compression test

...my question is this,is 110 to 120 lbs considered good compression??

yes... Remember this is a 2 stroke, not a car engine... compression ratio of about 6:1 as opposed to 8.5:1