Mercruser Raw Water pump problems
 

I am having a lot of problems burning up the rubber impeller on the stock pumps.

Everytime I start the motors [Whipplecharged HP500EFI's] I am scanning the Sea Strainer's.

I have to take the motors to about 1500 RPM to see water in the stainer's, in fear that I will burn-up the impeller again.

Does anyone have a solution?

Steve

Check for a crack or bad seal on your water pump housing.

Temporarly install some clear hose inline (raw water supply) near the thermostat housing to check for air leak.

Is there water in your strainers before you start your motor's or are they draining out after you pull it out of the water?

If you are running Bravo's, and using the drives for the water pick-ups. You might want to pull off the elbow on the inside of the t/a, where the main water line goes, and see if that hose isn't half pluggeg up.

There was a thread a few weeks back about the new 496 HO's having to rev up to about 1500 to "Prime" the pump just after start. If they sat an idled they would melt. Look for it maybe you are having the same problem.