COMPRESSION LOSS IN #3 CYLINDER

[marty36]

COMPRESSION LOSS IN #3 CYLINDER

I have a 1987 85hp Force outboard with 135 psi in #1<br />130 psi #2 and only 35 psi in #3 cyl the engine some times runs great and other times it stalls fequently. There is a distinctive knocking sound<br />when at low idle disapears at fast idle. there is a white steam coming from exhaust. boat still has a lot of power although. could it be the head gasket or how could i check to see if it is the compression rings

 

[roscoe]

Re: COMPRESSION LOSS IN #3 CYLINDER

Re: COMPRESSION LOSS IN #3 CYLINDER

Perhaps you can see some damage through the sparkplug hole.<br /><br />What does the #3 sparkplug look like? clean?<br />If so, suspect head gasket.<br /><br />You will have to pull the head to be certain.<br />Hopefully there is no damage and all you have to do is clean the surfaces and install a new gasket.