I have a Mariner/Mercury 3 cylinder, 90hp, 2 stroke engine (clamshell cover) and it has low compression ranging from 65 psi to 75 psi on all three cylinders. The engine starts up easy and when it runs it seems to run quite good except for one cylinder, and that comes on at higher revs and cuts out intermittently. With compression that low what should I do with it? Rebore? New head?
I was told that I may have a reed valve that is sticking, would that make it misfire on one cylinder, or cut out and fire up when at higher revs?
Im not an expert when it comes to outboards but I have done a lot of work on car engines. I have bought a second hand head that looks fairly easy to swap over but is there anything else I can try before changing the head?
I hear of de-carbonising the engine with sea foam, or quicksilver power tune, would it be worth trying that first? Perhaps it could stop the reed valve from sticking.
It is the low compression that is bothering me the most.
Thanks for reading.
I was told that I may have a reed valve that is sticking, would that make it misfire on one cylinder, or cut out and fire up when at higher revs?
Im not an expert when it comes to outboards but I have done a lot of work on car engines. I have bought a second hand head that looks fairly easy to swap over but is there anything else I can try before changing the head?
I hear of de-carbonising the engine with sea foam, or quicksilver power tune, would it be worth trying that first? Perhaps it could stop the reed valve from sticking.
It is the low compression that is bothering me the most.
Thanks for reading.