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Looking for compression specs
1987 135hp all stock Mercury
my gauge shows 118-120 , 2# varience between all 6 holes
weak battery , cold engine , throttle open
Thanks

That sounds about right for stock heads. If in dought take a leakdown test.

leakdown test tell u nothin really all that really shows is the there is a lil wear

but yeah them specs are good for stock heads

Thanks for the info
my clymer book does not show any numbers as a guideline

lundocno wrote:leakdown test tell u nothin really all that really shows is the there is a lil wear

but yeah them specs are good for stock heads

Can you eplain how a leak down isn't a better test that compression.