Hello,
I have an old 25 Bertram with twin 4.3 L Mercruisers and Alpha I drives. This past summer I had exhaust manifolds go bad on the port motor and had severe water intrusion. I have replaced the manifolds and changed the oil several times. Now I am seeing some surging in the rpm's in the cruising range of about 2800 (maybe 100 to 150 rpm surge) and the number 6 spark plug looks to be oil wet. I checked the compression and all appears to be normal (I say normal but the number 6 cylinder had noticeably lower compression after just the first compression cycle, after 4 or 5 compression cycles all cylinders were in the 150 to 160 psi range). I'm wondering if I could have damaged the intake gasket or something else. The motor is a 1998 with about 350 hours. It has the 4 barrel carb. Any advice would be greatly appreciated. Thanks.
I have an old 25 Bertram with twin 4.3 L Mercruisers and Alpha I drives. This past summer I had exhaust manifolds go bad on the port motor and had severe water intrusion. I have replaced the manifolds and changed the oil several times. Now I am seeing some surging in the rpm's in the cruising range of about 2800 (maybe 100 to 150 rpm surge) and the number 6 spark plug looks to be oil wet. I checked the compression and all appears to be normal (I say normal but the number 6 cylinder had noticeably lower compression after just the first compression cycle, after 4 or 5 compression cycles all cylinders were in the 150 to 160 psi range). I'm wondering if I could have damaged the intake gasket or something else. The motor is a 1998 with about 350 hours. It has the 4 barrel carb. Any advice would be greatly appreciated. Thanks.
