MERPOWER-Avoid Cooler Plugging

When the raw water pump fails, which is usually due to running dry, the impeller must be replaced. But wait! You must find and remove the pieces of the failed impeller that flowed down stream from the raw water pump. Until you retrieve these pieces, you can consider the water flow from the raw water pump to be plugged.

This plugging will cause overheating of the transmission, the engine and also the wet exhaust system hoses and related plumbing.

As the above photo shows, this transmission oil-cooler, the first heat exchanger in this system, was eighty percent plugged. Transmission overheating and failure was the result.

After clearing the blockage, the next step is to lubricate the new impeller with mild liquid soap before installation of the impeller. Finally, run the engine for a few minutes to wash the soap from the system.

MERPOWER-Using Your Engine As A Bilge Pump

Turn Your Engine Into a Bilge Pump

If your bilge pumps get knocked out and the boat is filling up, remember this: By re-plumbing your engine’s raw-water pump, it is possible to take water from the bilge and pump it overboard.

Simply detach the raw-water intake hose from its sea cock (after closing the sea cock) and plunge it into the bilge. Start your engine and monitor the water level, to be sure your engine has plenty of cooling water.

Be Sure to put some kind of screen or strainer over the raw water pump suction hose, to avoid plugging.