Check the oil for contamination, if its greyish and there is a marshmellow under the oil cap, quit running it immediately!

There is no quick fix for your situation. Topend must come off to deteremine where the problem is. You might get lucky and only have a busted head gasket. If engine has never been apart things might be easier and cheaper to fix.

Anyways, head has to come off for inspection. The gasket will show the failure plain as day if its the gasket. If the head is eroded, again it will be quit obvious. If the head is cracked....that makes thing tougher. Any combustion chamber that looks different than the other 3 is the problem cylinder.

No easy bets on the point of failure until the head is off.
These days, even a new head casting and gasket set are readily available from Engnbldr without breaking the bank. Tear down and reassembly arent TOO time consuming providing you have the tools.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />