I looked at the replies, and I think Bill and specially Den are onto
the likely cause - a direct route from the block to the intake
manifold - not your average problem, but still a bear to sort out, I
expect!

Brian W

On Thu, 29 May 2008 23:03:16 -0400, "MC" wrote:

Brian, Bill, Den,
Thanks for the ideas. To answer your questions, the plugs all get fouled up
equally. If I idle for long, I'm in trouble. The plugs get bad and it
starts missing. I'll have to check the fuel pump and intake manifold for
leaks, along with the PCV valve. It does seem odd that all cylinders foul
the plugs equally, if rings were suspect...unless all 8 cylinders were worn
the same. I have to get some time to take things apart and look around.



"den" wrote in message
...
Hello George:
I had the same indications. Pulled the engine, and completely
rebuilt it anyway. Invited an old salt (Al D.) over to my boat, and he
interviewed me over a sixpack. He took another swig on his beer, and
said "intake manifold". Tryin to catch up I took 2 more swigs, and
said No Way. We eventually ran out of beer and I removed the Carb, and
took a flashlight to the intake ports. One was stepped up, and
couldn't tell if Al was right or not. After removing the intake
manifold I rolled it over to find a tin plate on the bottom. I popped
the rivets holding the tin and lo and behold there was a hole about
the size of 2 golf balls in the cast iron. It seems that if you do not
get the engine hot enough to evaporate the moisture there it will
definately rust it away. I found the same situation in the port
engine. This brings back fond memories of San Diego, and Al.
I aint no "old salt" but I hope this expands your thinking.

Den 48ftYF EAGLE
http://www.densnet.com