running hot

[woody12]

I have a 1989 35hp force outboard ! ran hot 1 day took home removed lower unit installed now water pump impeller.Took boat out still got hot replaced all fuel lines and disconnects thought possible vacuum leak making engine run lean but no luck?Now put on tell tail line , now have motor in barrel of water when motor cold water flows good from TT line as motor gets hotter water turns to steam! did compression test top cyl 120psi bottom cyl 122psi . anybody out there have any ideas why it gets hot?

 

[Nordin]

Was the old impeller in pieces when you changed it to the new one?
If, there could be pieces of the vanes blocking in the water jackets. There can also be other things blocking and not give enought waterflow.
Try to blow with compressed air through the cooling system.

Take a look at the impellerhousing to. If the surface in the housing is pitted the impeller may do not pump enought water.

 

[jerryjerry05]

You run in shallow water?
Maybe through the mud?
If you did the exhaust chest might be clogged.
What did the old impeller look like?
Pics?
There's no thermostat in that motor so try flushing the thermo housing.
No thermo but it has a housing for one????

When you reassembled you get all the parts back in?
Pics?

 

[woody12]

There is no thermostat, When I took lower off to replace impeller I flushed up supply pipe ,down thermo housing,thru 2 small ports on back of motor. Old impeller was in one piece,impeller housing has small pits in it but cleaned up real good using scotchbrite .Where is the exhaust chest? or did it get clean on the back flush? I am a diesel mech by trade ,But outboards are new to me? and yes I buy american cars!

 

[woody12]

Well guy,s I pulled the head off and the fiber on the gasket is squeezed out from under the fire ring on gasket,Due think this could be the over heat problem ?

 

[jerryjerry05]

Pics of the "squeezed" Unless it's blocking the passage it's probably not causing the heat.
The exhaust chest is on the port side of the head.

I'm working on a 40yam for overheat.
The impeller was in fairly good shape.
Removed the chest and about 2 pounds of sand and crud was in there.

If you take yours apart???
Be VERY careful when you do.
The 1/4-20 bolts break off just looking at them.
Start spraying PB or WD and turn slowly and maybe use some heat???

 

[woody12]

will try exhaust have got pix in email but dont no how to send them

 

[jerryjerry05]

Sent U a pm

 

[jerryjerry05]

No Title

Here's a pic of the gasket.
From what I see I don't think it would cause an overheat.
But a blown gasket was in your future.
The fire ring was the only thing left in one piece.

 

[woody12]

looks like exhaust is next

 

[jerryjerry05]

Like I said. Be very careful when you start removing the bolts.
WD or PB. Start spraying and using a small torch to heat them and tap with a hammer.
Then very slowly try undoing the screws.
If they don't come easy spray and heat again.

 

[woody12]

took it apart bolts came out easy ! exhaust chest is clean! ran water thru it anyway just make sure, Any other ideas?

 

[jerryjerry05]

Is the pump housing ok?
Are all the parts there?
Back flush so it comes out the pickup tube.

 

[woody12]

finaly got her out on the !she ran fine . Thanks for all the help ! Woody