Take a look at my cylinder head...

[john7bon]

1971 Evinrude 6HP Fisherman.

I blew a head gasket minutes after inheriting the engine. This is what I see after removing the head. Notice the difference between each cylinder head. They cylinder that still had compression is rich in carbon deposits, while the cylinder that was effected by the gasket rip is "clean", with a fair amount of rust. Their respective pistons look the same way.

What does this tell you guys? I would have expected both to have carbon build-up.

Also, what can I use to clean the the head and top-of-pistons prior to putting everything back together?

 

[john7bon]

Re: Take a look at my cylinder head...

I'm starting to think that the head gasket had been compromised enough to let moisture in that cylinder, but not enough to prevent that cylinder from firing. When I got the thing and fired it up for the first time in years, it finally blew completely (on its maiden voyage with me, it ran okay for about 10 minutes, then petered out to one cylinder).

 

[R.Johnson]

Re: Take a look at my cylinder head...

The clean cavity is from water washing away the carbon. Is the engine running OK now?

 

[john7bon]

Re: Take a look at my cylinder head...

Don't know yet. Should be getting the new head gasket in the mail today. It was a pretty big tear in the gasket, extending all the way out to the edge of the engine. Must have been drawing water in through there.

That being the case, do I need to do anything special other than put the thing back together with the new gasket?

 

[tashasdaddy]

Re: Take a look at my cylinder head...

dry it out, reassemble.