"jamesgangnc" wrote in message
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wrote in message
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On Jul 25, 8:03 am, "jamesgangnc" wrote:
"JR North" wrote in message

news
As The Wrench Turns...
Got the heads off; and posted some pics on the metalworking Dropbox
at:
http://www.metalworking.com/dropbox/
See valve.jpg 3 pics
No damage to the cylinder wall or head, and just a couple minor dings
on the piston crown. Lucky me.
JR
HOME PAGE:
http://www.seanet.com/~jasonrnorth
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That's a lot of rust on that head. Other one look like that?

That's what I thought......certainly makes think about whether this is
common with I/O's. Never owned one, so I don't know. I believe he said
he fogged it, didn't he?

Not the ones I see. But then I'm in "trailer boating in lakes" land here
in Raleigh. Might be sitting in a slip in salt water does it. There is
going to be one or two cylinders sitting with the exhaust valve open when
the engine is shut off just about everytime. If the boat sits in water
then the humidity is going to remain high through the exhaust system so it
will get high in the cylinder as well. It's not specific to an i/o
though, any boat with an inboard marinized auto engine is going to be in
the same situation. I would have expected the small amount of oil that
gets past the valve stems to keep the valves from sticking though.

The main issue specific to i/os in a slip is that the outdrive sits in the
water. Most outboards can be raised enough to get the entire engine out
of the water.

Regular use would probably reduce the problem. And that might explain why
commercial fishing boats run marinized auto engines for a long time
without problems.

The number one reason this happens is that folks try to extend the life of
their exhaust systems beyond recommended limits.