Mercruiser 165 - Exhaust - Water Separation Tube

[masonh]

Hello everyone, I recently bought this 1976 22' StarCraft Islander last August. It sat for 8 or 9 years. Great compression, 155 psi. per cylinder.

It has taken some time to get it running - the carburetor had to be rebuilt, mechanical fuel pump rebuilt, ignition and pertronix ignitor rewired. Now I have a running motor.

I've run it half a dozen times with the garden hose hooked up to the stern drive, and continue to verify that the engine is going to behave consistently before driving down to the launch.

Yesterday I discovered a new problem. After warming up the engine, the water separation tube begins smoking. Not the type where a crack or hole is venting, or loose connection, but rather the type where you see the entire surface area off-gassing. Stinky, burning rubber smell. It's getting so hot that the rubber is burning. So bad I shut it down and reached for the fire extinguisher.

My first inclination would be to go and buy a new water separation tube. I was hoping someone might know if there is some other issue taking place before I go throwing parts at a symptom.

Thank you!

Mason

 

[alldodge]

Your pic

Looks like the exhaust boot which goes from the exhaust elbow off the manifold and connects to the exhaust pipe which goes out thru the drive. In this pic it is connected where the OT is listed. If this is getting hot, then you do not have water going thru the motor of sufficient volume. First guess is you need a new impeller, or if it was replaced then the tube which connects the upper to the lower half was not installed correctly

 

[Bt Doctur]

the exaust tube only gets that way if no water is exiting the motor

 

[masonh]

No Title

AllDodge and Bt Doctur - thank you for the replies. Indeed, it was the impeller.