Re: Water Pump
Sir,
Though I'm not familiar with your particular engine, its age and style are common. These general guidelines might help you. Remove the foot of the outboard. The foot is the bottom unit that houses the propeller and transmission. Inside, on the driveshaft you'll find a round seal around the driveshaft leading into a housing at the top and inside the foot itself. That housing is the water pump. Open up the housing, inside you'll find a "fan" of flexible plastic/rubber contained in an eccentric hollow. The fan is called the impeller. Impellers are "consumable" parts, they need to be replaced every couple of years. The impeller is keyed to the drive with a woodruff key fitting into two slots, one slot in the impeller and one in the drive. Carefully pry off and out, the old, non-functional impeller. SAVE the key, they're a bit harder to find. Clean the driveshaft with solvent and a wire brush to make installing the new impeller easier. Flush away the solvent with soapy water, and rinse, you don't want it to settle into degradeable seals or gaskets. Check that all intake and exhause passages of the coolant flow are clear of obstructions. Pieces or even whole vanes can find their way into the passages and block them.
Since so many are replaced each year, your local auto parts store that has a "marine" catalogue is likely to carry the part. Take your old impeller with you and make sure that the new part has the same internal diameter, that the key fits it, that the length and heights of the vanes match.
If there is a gasket, replace, don't re-use it. Sheet gasket material will work if carefully traced and cut from the original. I put a VERY thin coat of "Forma-Gasket" marine (blue) sealer on both surfaces, that hasn't yet caused me a problem. Insert the key, the new impeller and button the unit back up again. Pay special attention that the driveshaft, the water passages and the bolts are correctly aligned. Bumping, slightly rotating, the flywheel may help with that. The vanes on the impeller will need to be compressed to fit into the hollow housing, don't force them as they'll easily tear. I compress mine with carpet thread, it can be readily snipped and removed after installation.
