On Fri, 18 Jul 2003 19:52:59 GMT, "John Q."
wrote:


1995 Mercruiser /Alpha One, V8 5.0

Ran fine for a while. It's been slipped for about a month. I took it for a
spin last weekend and it started overheating right as it goes up to plane.
It runs cool at slow/non-planing speeds, but as soon as it starts to get up,
the temp shoots way up. Taking the boat out of the water, there is a TON of
crud on the bottom and on the sterndrive (algae mainly).

I'm going to try and tackle this one myself (after having already spent way
too much on it). I bought a service manual, and it looks like there are a
bunch of things that could be wrong. Here are what I think the primary
suspects are :

1) Busted thermostat.
2) Busted water pump.
3) Busted impeller. (crud getting sucked up into the intakes??).
4) Clogged exhaust? ( " " ")

I'd like to start checking each place, but since each place takes a
significant amount of time/work to get to, I was wondering whether you guys
could give me a hint as to where to start first.

Any help would be greatly appreciated.

Thanks!
JQ.


1a) should be to check the coolant water intakes, and see if they are
blocked by "crud". That would be my first check. If the water can't
get in, it can't cool.

If it has been starved for water, you may have toasted the waterpump
impeller. Clean that lower unit first, and try to get the crap out of
the intakes.

You didn't mention if it was slipped in salt or fresh.
Good luck,
noah

Courtesy of Lee Yeaton,
See the boats of rec.boats
www.TheBayGuide.com/rec.boats