Reply To: Power Head Cross Reference for 1958 Evinrude Fisherman 5516

[Don]

Replacing the rings is a judgement call for sure.  Do not try to use oversize rings and file them down.  Perhaps the rings were replaced when this unit was apart before explaining the tight end clearances.  I’m sure there aren’t many hours on this unit since it was apart or that lower rod would have probably gave way from the crank and poked a hole in the block.  I am suggesting using new standard rings “just in case” the previous repair included some peculiar/oversize ring replacements.  You want to make sure the ring grooves on the pistons are totally cleaned out also,  oftentimes old rings are used to do that job (break one ring and use its sharp edge in the grooves).

Did you ask Ed if he has new rings?  I will look online also.  Again, replacing the rings is a judgement call for sure.  Using the old rings will be fine,  provided you ensure the ring grooves are clean so there is no debris/carbon pushing the rings out into the cylinder.  This can be done by installing all the rings on the pistons, then rotating a straight edge around the piston to ensure none of the rings are being pushed out past the edge of the pistons.

Again, don’t forget to make sure you have four new lock rings for the new rods, along with four new wrist pin retainer clips.   Review the procedures for pressing those wrist pins out.  Again, you must press the pins out from the tight side through the loose side, then press them back in the same way.   You will want all new powerhead gaskets also, and please make sure all the parts for that lower power head seal assembly are there, replace the carbon seal oring and the round driveshaft gasket.  You will want to check the igntion and fuel system as well.  You will want to review the procedures for using the OMC gel seal to seal the crankcase halves, or use the 847 sealer.