I need to find out the part number for a replacement water pump for a 1966 3 hp Johnson outboard.<br /><br />The below information is from the engine plate<br />model number is JW 21E<br />serial number is E2695473<br /><br />I recently recieved the motor and my research of the model number indicates that it was built in 1966. If this is wrong please let me know.<br /><br />I was able to get the engine started but I do not think the water pump is working correctly.<br /><br />Thanks for your assistance<br /><br />BL Williams
)<br /><br />Anyway, on to your question. The water pump is replaceable by PN 379770 (entire pump) or PN 379763 (impeller only) from your local Johnny/Rude dealer or an online dealer like ishopmarine.com or maxrules.com. The aftermarket part 18-3201 (water pump except for the aluminium cover, so wear plate, grommets, impeller, etc) or 18-3001 (impeller alone) are available from Iboats, NAPA autoparts, etc. Personally I have no preference between aftermarket/oem for the water pump parts.<br /><br />When you have the leg of to replace the impeller - first, don't ever lift up on the driveshaft while the impeller housing is off. Getting the driveshaft back into the lower unit can be a real problem. Second, blow up through the water tube to make sure the passages are clear.<br /><br />When you've got it all working, you should get a mist of water out with the exhaust through the idle exhaust relief ports in the leg.<br /><br />Hope this helps!