picture 2

picture 3

picture 4 Any ideas why this would happen. If I don't have a good reason for the warranty company, its my problem.

If both engines look like this I would suspect bad fuel; low octane or water in the fuel. If just one, it could have run lean or overheated bad.

We had water in a suppliers tank (it was a gasohol automotive type), and the water in the guys tank blended with the gasohol, which can reduce the octane rating like 10 points. Several boaters were reimbursed for their repairs by the fuel company, Sunoco I believe.

You should have your fuel checked and pull the fuel filter and cut it open. Gasahol can clean everybody's tanks and all the crud will clog the fuel filters. This can cause fuel starvation.

If you can't find a cause, you may blow up again.

Check with the last place you got gas, to see if others had any problems. Supercharged engines are more inclined to have problem.

Good luck, John B

Not real sure what I am looking for in picture #4. Is it picture of between 1 & 3?

Picture 4 is a zoomed in pic of the third picture. Those two pic's are from the other side of the engine showing that gasket about ready to go also.
Dan

We will be taking the heads off the port engine soon. It should tell us allot.

I found out the previous owner of my boat lost a fuel pump (the electric one) just before he traded it in. Could this cause the gasket to start to fail?

Thanks for the pictures and explanation Dan.

Lean fuel can cause detonation witch can cause all kind of problems. Do the pistons show any signs of pitting, or are cylinder walls got scratches in them?

The gasket failing is really a safety valve. I would rather have the gasket fail or spark plug blow out then the other damage detonation can do.

High engine water temps, high intake temps, lean fuel, low grade fuel, & too hot of sparkplug are some of the things that cause detonation.

You're right, better to have the HG as a fuse...

Has anyone ever considered a dual / parallel electric FP system with check valves so if one dies the other carries the load and prevents this type failure?

We do it with race jeeps (rockcrawling) and have had good luck. This way you could just bench check your pumps once a yr or more if you wanted to.

Are there relibility issues with this FP? is it the same FP merc uses in other apps?

Roger, check both the block and the heads with a good straightedge to see if either is beyond the allowable tolerances. I think the tolerance for the head is .003 max.