I saw this parts breakdown a couple days ago, but I'm still confused.
The thermostat shown in this picture is not on my engine. If it was
there, it's been removed. There is one in the top of the thermostat
housing that sure looks like it was cast with it in there (which seems
like a very odd thing to do). It seems to control the water flow to the
exhaust manifolds.

This brings me to a flow question. It *looks* like fresh water is pumped
up from the outdrive to the thermostat housing. The water pump on the
engine picks that up, pumps it through the block/heads/intake and back
to the thermostat housing. Then is *looks* like the thermostat in the
top of the housing opens at whatever temp to let the water out to the
exhaust manifolds to be replaced by fresh water. Does this seem right?

Wildest Dream wrote:
http://216.37.204.206/Actionsports/O...pe=13&A=11&B=6 hear
is a parts diagram the thermostate is #56 $15.99 . the only ring I see
below it is an o-ring looks to me as if it pops up or screws out. My book
don't go into any real detail, all it tells u is to drain the system, (Seloc
8-15 in the 1985 to 1995 OMC Cobra & King Cobra stern drive manual). I don't
see how taking the intake manifold off will help much just to turn it upside
down and hope it falls out, seams like alot of work to me. Of course I never
replaced one in a boat but I would still try to pry it out insted of going
through all that trouble. If its in a well then try some c-clip plyers, if
not just pry it up with a screw driver. it may be garbage when u get it out
but a new one that looks to just drop in @ only $16 is insurance enough for
me. But then again it isn't my boat. Good luck.


"Jim" wrote in message
om...

I took my '88 4.3L out for a cruise today before storing it and had
overheating problems. So I brought it home and hooked it up to the
flusher. If I pull the inlet hose on the thermostat housing there is
water when it's running. So I pulled the thermostat housing expecting
to find a thermostat in the intake manifold, but there isn't one
there. Rather there seems to be one built into the housing that can't
be changed? I must be missing something, right?

Jim wrote in :

I saw this parts breakdown a couple days ago, but I'm still confused.
The thermostat shown in this picture is not on my engine. If it was
there, it's been removed. There is one in the top of the thermostat
housing that sure looks like it was cast with it in there (which seems
like a very odd thing to do).

If this is anything like my Volvo Penta 4.3 (and I believe it is since the
Volvo Penta was derived from the OMC Cobra) there is a retaining ring, its
just very hard to see. I had the same thought as you, that the thermostat
looked like it was cast in place. But I also knew that this was unlikely,
so I searched for what I figured must be there, a retaining ring. Couldn't
find it, so I took the whole piece to my friendly marine shop. When I
asked the counter guy how to get the thermostat out, he said "there's a
retaining ring." He took a tool with a point akin to a dentist's pick and
inserted into a groove just next to the thermostat which I hadn't seen
before. Probably obscured by corrision/debris. The ring is rubber and he
slipped the "pick" under and behind it and lifted the ring out in about 5
seconds. I felt pretty stupid but grateful. The thermostat pulled right out
and the new one dropped right in. The ring was in perfect shape and the
shop didn't even want to sell me a new one, so we popped it back in and was
done. Bolted the housing back on the engine and was in business.

Thanks, I got it out last night. As you mentioned, it was covered with
scale and looked like it was just part of the housing.

akheel wrote:
Jim wrote in :


I saw this parts breakdown a couple days ago, but I'm still confused.
The thermostat shown in this picture is not on my engine. If it was
there, it's been removed. There is one in the top of the thermostat
housing that sure looks like it was cast with it in there (which seems
like a very odd thing to do).


If this is anything like my Volvo Penta 4.3 (and I believe it is since the
Volvo Penta was derived from the OMC Cobra) there is a retaining ring, its
just very hard to see. I had the same thought as you, that the thermostat
looked like it was cast in place. But I also knew that this was unlikely,
so I searched for what I figured must be there, a retaining ring. Couldn't
find it, so I took the whole piece to my friendly marine shop. When I
asked the counter guy how to get the thermostat out, he said "there's a
retaining ring." He took a tool with a point akin to a dentist's pick and
inserted into a groove just next to the thermostat which I hadn't seen
before. Probably obscured by corrision/debris. The ring is rubber and he
slipped the "pick" under and behind it and lifted the ring out in about 5
seconds. I felt pretty stupid but grateful. The thermostat pulled right out
and the new one dropped right in. The ring was in perfect shape and the
shop didn't even want to sell me a new one, so we popped it back in and was
done. Bolted the housing back on the engine and was in business.