Water in top cylnder, HELP!

[san dimas]

I have a 1997 Force 75hp. The top cylinder has water in it so I replace the head gasket. The top piston shows signs of pinging, top of piston looks shot peened and all the carbon is gone. The 2 lower cylinders look normal. The old gasket didn't show signs of leaking past the fire rings yet the rest of the gasket was pretty corroded. The head was not warped. I ran the engine with the new gasket and it ran OK for about 30 seconds and then started miss firing. The top plug shows signs of water again. So I thought it was the exhaust cover. I took it off (breaking many bolts) and can't see any obvious signs of water getting in the exhaust chamber. Plus I have read that exhaust cover leaks usually affect the lower cylinders first. When I had the head off, I didn't see any cracks in the cylinder. What am I missing?

 

[pnwboat]

Re: Water in top cylnder, HELP!

Couple of questions.

Have you done a compression check? Need to verify that the compression in the top cylinder is OK. If not, you may find that the water leak is a minor problem compared to low compression. You know....bad/broken rings, scored piston or cylinder wall etc.

You mentioned that you didn't see any signs of water in the exhaust cavity. Was this after you replaced the exhaust cover gasket and tested? There may be a stainless steel baffle that is sandwiched between the exhaust cover and the block. Sometimes they develop a crack and leak water into the cylinder.

 

[Jiggz]

Re: Water in top cylnder, HELP!

As PNW said, do a compression check first post them so we can do a diagnosis. Also if you can post a pic it will help very much in troubleshooting.

 

[san dimas]

Re: Water in top cylnder, HELP!

Compression was 135,130,and135. Every nut and bolt on this thing is really corrode so it makes every thing I do a pain.

 

[Jiggz]

Re: Water in top cylnder, HELP!

Those compression numbers look good. I can only think of three ways water can get into the cylinder, a leaking gasket head, leaky exhaust plate and a cracked cylinder. Of course there is also the warped head which can cause a leaky head gasket. Since the engine misfires, it would indicate there is a serious water leak otherwise the engine would have ran smoothly except the cylinder, head and plugs will be shiny clean, due to "steam cleaning" caused by water vapors.

You might have to do a closer inspection to locate the source of the leak. The only other thing I can think of is put it back together and run it for about 30 seconds with the #1 plug disconnected (intentional misfiring), shut it down and let it sit for up to 48 hours. Remove the head again and inspect #1 cylinder for traces of "rusting" and hopefully will indicate the source of water intrusion.