TOPIC: 63 Merc 1000 rings

Hey Old Merc Guys,

Heard from a friend who is working on a 63 1000.
He had low compression on cylinder 1 so he pulled off the transfer port cover.



And sure enough a section of the ring is gone.


He says the 1000 parts diagram shows 3 rings although the parts list shows total qty of 12.

The 800 manual I have shows the same.
I have 64 650 manual which shows 2 rings.

Any ideas on this discrepancy?

Thanks,
Terry

The first run had 2-ring pistons and IIRC the rings were 3/16" thick. Next run also had 2-ring pistons with 5/64" thick rings. You have to go by serial # with these. Probably the switch to a 3-ring piston was with the '65 models but don't hold me to that! At any rate, the bore size is the same and you could use 3-ring pistons in that powerhead as well.

The rod size on the Big End of all the 90 c.i. engines is the same, so you could use whatever piston/rod combination you find.

HTH.............ed

Thanks Ed,

Good Info.

S/N on this is 1669754 and it’s actually an early 1964.

The guy who working on this motor found a link to a 1000 rebuild that had both 2 & 3 ring pistons. Blimey!



Terry