Should I replace the bearings?

[kryck]

Hi everybody

I'm O.D boring my 50 hp 1998 merc since the two mid cyl's are slightly oval/out of round. Questions for all you engine experts:

1. Should I rebore all four cyl's although the top and the bottom seems just fine (when measuring)?
2. Is there any third party manufacturer of pistons and rings or do I have to buy original?
3. Should I replace the rod bearings and the crank shaft bearings? How do I know if they're good/bad?

Thanks

 

[kryck]

Re: Should I replace the bearings?

Forgot to mention that this is a four stroke ELPT. I've found plenty of third party pistons for two strokes (GLM, Sierra, Mallory) but none for four stroke pistons.

 

[Faztbullet]

Re: Should I replace the bearings?

1. Should I rebore all four cyl's although the top and the bottom seems just fine (when measuring)?

Yes...reason is balance issue and 4 stroke.....

Is there any third party manufacturer of pistons and rings or do I have to buy original?

Not at this time are aftermarket pistons offered,you have to go OEM.......

3. Should I replace the rod bearings and the crank shaft bearings? How do I know if they're good/bad?

Yes you need to change main and rod bearings, you will need manual to get the tolerances on the colored bearings(brn,blk,blue) It better to have a machine shop measure and set this up for you as its a pain if you dont note where colors/bearing came from.