1976 Evinrude 15 HP Lower Unit Troubles

Hey there,

I'm really hopeful one of the OMC gurus can help me out. Last week I purchased an Evinrude 15 hp model 15604R that hadn't been run for a while. The exterior looked nice and it turned over so I took a gamble. The previous owner bought it from someone else but was never able to get it running so I have virtually no history on this motor. I performed some light cleaning of the carb and ignition components and it fired right up. It didn't pump any water so I dropped the lower unit and saw it was filled with a heavy layer of greasy sand. I cleaned it up as best I could but the shifting didn't feel right so I decided to have a look inside. The good news is the gear case had good grease and the pinion and gears and propeller shaft all looked great. I do have a few missing parts to contend with. The two balls at the end of the detent spring are gone and there's just a single thrust washer on the pinion. The parts diagram indicates that there should be two washers, 0318800 for the lower bearing and 0318699 for the upper. I'm not sure which one I have and which one I need to go looking for. Any ideas?

Many thanks for the help.

Re: 1976 Evinrude 15 HP Lower Unit Troubles

The service manual for this motor references a pair of chamfered thrust washers that sandwich the pinion thrust bearing. I don't know if it matters, but the single thrust washer I pulled out of this gear case is flat on both sides. A poor handyman's substitution or was there another design for this lower unit? Some OMC part suppliers say these washers are obsolete so I'm leaning towards the former. I've combed through a number of parts diagrams covering different years and all look to use two thrust washers on the pinion gear. Any help offered would be appreciated. Thanks!

Re: 1976 Evinrude 15 HP Lower Unit Troubles

Here you go.
http://www.marineengine.com/newparts/part_search.php?part_num=318800&x=11&y=9
http://www.marineengine.com/newparts/part_search.php?part_num=318699&x=10&y=5