different cylinder pressure

[stul]

hi
just finnished tidying up wiring,and a few other jobs on my little rib before a trip down the Menie straights this weekend.Borrowed a Pressure Gauge and with help of my girlfriend descide to see what pressure i was getting,we are talking a 1978 Mercury 40 hp 2 cylinder engine,which has had its problems but once up and running goes fairly well 24 mph on the plane.
Took reading top cylinder 110 took reading bottem cylinder barly 75 ?:the engine seems to be running fine starts well and went well two ago,will this last.??? any advice welcome
Stuart

[fast fred]

she stuck a ring sounds like , not makein 40hp, they don't fix them selfs.

[Nos4r2]

Originally Posted by stul

24 mph on the plane.

Should make at least 30-35mph...

Originally Posted by stul

Took reading top cylinder 110 took reading bottem cylinder barly 75 ?:the engine seems to be running fine starts well and went well two ago,will this last.??? any advice welcome
Stuart

Fred's right. If it aint a stuck ring then the bores are scored.


Chuck a capful of Redex down the plughole with the engine warmed up and tilted. Then put a full can of Redex in a gallon of premix and use it all at about 1/3 throttle (ie just on the plane).
Retest it after that. It should improve if it's carboned up. If it's not rhen forget it...