cooling problem

[David]

I started with an overheating problem at Hight RPM's. Per Ken at your shop, I replaced the impeller and installed a thermostat (P.O. had removed). Everything ran fine until suddenly the water at the exhaust quit pumping. (this had happened once before but cleared up before I could investigate.)
I checked the impeller, but it was fine and water was siphoning into the pump ok. I checked the thermostat and nothing was clogged there, and there was plenty of water.
I ran the engine until the thermostat opened and still no water out of the exhaust. So it seems I am clogged somewhere between the exhaust manifold and the muffler. Any suggestions as to the most obvious place to start looking?

[Don Moyer]

David,

Assuming that you have good flow through the manifold, you've pretty much limited your possible blockage to two possibilities: There is a blockage in the fitting on your exhaust system (probably the most likely), or the inner lining of your rubber exhaust hose is collapsing in and blocking the hose. This condition usually occurs within the first several feet of the hose.

Regards,

Don