260 ring service

[LakeFever]

Looking at a 260 that has good compression but is climbing to 100hrs so I’m thinking about replacing the rings and want to know what all is involved to do this being a nic block and all.

[Merc 2.5]

Surprised no one has jumped in Fer ya , never owned one, so Fer what it's worth ... main thing is roundness of cyl and nic condition, sometimes a rering turns into renic. If u have no experience or the tools u will need to send it to someone

[LakeFever]

A renic is out of the question and thats the thing I want to avoid. Plan is to do a leakdown and see. The owner says compression is tight and consistent across all holes. Seems like a real decent guy too but with the age and risk of a meltdown i'd prefer to re-ring t if I buy it so that is what im wondering about. There must be someone here who knows the correct procedure for this and approximate cost. Not looking for guarantees on the motor or the advice just an idea of what it takes to do a good job of it.

[Stoker boy]

You can pull off the reed plate and the heads remove the rod bolts and pull the pistons out through the backside. Set a bore gauge 3.500 tho. Check to see if the cylinders are out of round. Don’t forget the orientation of the rod and the rod caps. I believe the ring gap should be around 12 or 13,000 according to the book some people run them looser. It’s not all that hard to do.

[LakeFever]

So there’s no cyl refinishing at all just replace the rings and leave the bores as is?

[superboattwin250]

There’s a lot that goes into it to make it correct. What type of pistons, did the pistons shrink are the bores still round, is the nic worn or peeling by the ports. Top pinned or side pinned pistons ? Is it and older bottom guide motor. Lot to think about and it can get pricey fast.

[LakeFever]

Motors a 96 supposed to be still original as built by Mercury never rebuilt. I understand things can get out of hand quickly when tearing into such a thing. I’ll be sure to check it over reaaaaaaally well before buying. But I’d rather do preventative maintenance than wait for kaboom so I’m planning for a refresh if I get it

[Stoker boy]

Some people don’t like to hone out the cylinders some people do. If the nik is in good condition and the bores are relatively round you can run a nik hone without too much problem. Goodson sells special hones designed for Nic. The 96 motor I had came with Top guided rods mahale side pinned pistons. If their side pinned you will need to check to see if the locating pins are loose. You also want to check the pistons for roundness. I’ve never had wrist pins or needle bearings fail but you will want to check them for any excessive wear. Also check the rod bearings. You probably want to acquire a 260 manual so you can look at all the specs. If your pistons are OK there’s a guy named John Marles that can top pin them for you. It’s very critical to purchase the correct rings side pin and top pinned rings are different. John can explain that to you.

[rgsauger]

Where ya located?