compression on 1977 55 hp johnson

[TPyles]

Can anyone please advise what acceptable variation on the compression is between upper and lower cylenders on a 1977 55 hp Johnson model 55E77? The top cylinder is 125 lbs and the bottom is 150 lbs, I belive this is OK but I would like a second opinion before I go any farther, I just bought this motor and I would like to know before I continue to modify the rigging on my boat. Thanks again.

 

[JB]

Re: compression on 1977 55 hp johnson

That 25psi difference is more than the 15% variance recommended, TPyles, but I think it is acceptable.<br /><br />Because you haven't any history on the engine I would do a decarb and recheck it.<br /><br />Good luck.