I blew a head gasket on my bottom cylinder. I have a 1995 Force 40 hp 2 stroke outboard.
I checked the compression right before I left for the boat ramp. It was 140 on each cylinder. I launched the boat and docked it for the purpose of adjusting my idle mixture on the carb. I turned it all the way lean to all the way rich while in idle just trying to get a feel for things. I am new to boating and had it 1 and 1/4 turn out from full lean. I started her up and then revved it hard to check how things were running. I noticed the water stream was going full to weak intermittently and then eventually spitting. Water started leaking into the cowling (Was coming out gasket) I went home and removed the head gasket and it was blown. The rings and cylinders were all good but a ton of water got in the lower cylinder. My only thought is this happened from revving while set at too lean a mixture. Compression was 85 when I took it home. Still 140 on top. Any thoughts please advise. Thanks.
I checked the compression right before I left for the boat ramp. It was 140 on each cylinder. I launched the boat and docked it for the purpose of adjusting my idle mixture on the carb. I turned it all the way lean to all the way rich while in idle just trying to get a feel for things. I am new to boating and had it 1 and 1/4 turn out from full lean. I started her up and then revved it hard to check how things were running. I noticed the water stream was going full to weak intermittently and then eventually spitting. Water started leaking into the cowling (Was coming out gasket) I went home and removed the head gasket and it was blown. The rings and cylinders were all good but a ton of water got in the lower cylinder. My only thought is this happened from revving while set at too lean a mixture. Compression was 85 when I took it home. Still 140 on top. Any thoughts please advise. Thanks.