overheating

[Larry Mugford]

My engine is over heating again. It is a 11hp universal m-15 on a catalina 30 1982 raw water cooled. I have hauled out boat to inspect raw water thru hull and it was clean. checked all hoses on engine, checked thermostat, impellor on water pump was good. I also took exaust manifold off and got it steamed out. cant figure it out. It is running at about 175-180 should be at about 135-150. any sugestions , never had much water coming out of the exaust , mostly steams.Thanks

 

[Bob Chapin]

Might help

I don't know if you have already done this or not but I had a similar problem on my 1986 Cat 30 with a Universal 21. After trying all the things you mention, I simply flushed all of the coolant out and replaced it with fresh. I have not had any probelm since. I should have done the simple thing first.

 

[Don Flowers]

Options

It sounds as if you need to flush the engine with a cleaner , I think it's called marsol, or something like that, anyway, the water also goes through ports surrounding the cylinder walls and then returns out the exuast. one, or some of these ports could be stopped up. Anyway, this flush was designed to be recirculated through the system for several minutes, some as long as thirty minutes. The water is collected as it exits the exuast and recirculated to the inside of the vessel and ran to the intake water line. This flushes the entire system at once. If you are still confused as to how it is done E-mail me and I can go further into detail. Hope it helps.Don

 

[Dave Slepoy]

loss of water

one of the Catalina 30's at my marina had a cooling problem and they found that the hose AFTER the impeller took a sharp bend towards another part of the engine. There were small flappers from OLD impellers stuck in this bend decressing the water flow. Good luck