SUBJECT: Water Pump Impeller
Investigation of water pump failures has revealed that motors are being run out of water for one reason or another, including draining of the carburetor of fuel and draining the motor of water. Also some dealers are running the motors dry when checking electrical hook-ups when rigging boats previous to delivery to the customer.
Running the motor out of water for any reason is a dangerous practice and should not be done under any circumstances. Premature impeller failure will result as the rubber blades will not hold up running in a dry pump. The blades will scuff, get hot, and break off.
Also, if it is necessary to turn the motor over by hand during repair, be certain it is turned over in its normal direction of movement. Turning in reverse direction may kink the blades in a reverse set, and when starting the engine, damage to the impeller may result.