Water pumps

[parrott04]

Will this has always worked before so here we go, I am having overheating problems on a 440 starboard motor , it is new started it up it ran at about 1200 RPM for about 30min no problem then heated up and boiled over pulled the stat still did it checked the flow through the heat exchaner and it seems fine would like to replace the water pump but don't now where to find one any help? Thanks

[Trojan]

Doesn't sound like a waterpump to me. How can you have full flow through the heat exchanger and have a bad pump. I know you said you checked the heat exchanger. Check your heat exchanger on the transmission.They have very small tubes. There famous for this type of a slow over heat. Doesn't your motor have a double rubber impeller pump like the 318 has? I asume your 440 is a chrysler. Bill

[parrott04]

I think the pump on the motor is the same as the 318 is yours belt driven, that is the one I think there may be a problem with the raw water pump seems to have a good amount of flow I thought about switching the pumps out and see it it stops the overheating.

[41-Hatteras]

I had a similar problem with my DD. Mine would run at normal temperature at 1200 RMP, however at higher RMP's it would overheat. I check everything, impellers, water pump, suction, & heat exchanger. I took the heat exchanger out and it was 85% clogged. I soaked it in acid the same as used in swimming pools and let boil until it was clean, flush in clean water, reinstall and problem was gone. I did the port side also.