hi all,

I'm rebuilding an OS 50Sx, and I can't get the piston back in the liner. There's a champher on the bottom of the liner. I thought that this would compress the ring so the piston would slide in.

No luck. Is there a trick?

Regards,

Steve

Look on the piston and see if there's a small pin that holds the ring in one
location....if the ring is not positioned properly, it won't fit back on.

FBD.

I'm not sure if the ring is pinned on the OS50. It seems to compress back into the slot okay

S

On the 50SX there is a spring pin stuck straight into the ring groove on the left rear corner. The ring gap must be placed at this position or you cannot get the piston/ring up in the sleeve.

Enjoy,

Jim

Use lubrication around the hole (bottom of the liner) and a bit on the piston. That will help!
Doesn't take much, you could even wet it with a spot of engine oil!

I got mine in WITHOUT knowing about that spring thingy. My 50 now is junk!!!! *****...

Steve:

The 50 SX ring, as stated by several above, is pinned. If you force it the liner, piston, and ring are immediately converted into junk. OS prices being what they are, once you do that a new Magnum 52 is a far better deal.

If you get everything lined up properly it will slide together easily and give you more good service.

Bill.

....[X(]....I didn't think you could get the liner down over the piston, with
the ring not properly located. []

FBD.

You most certainly can. You then have a nice carb left over and just like the guy stated above can go out and get a Magnum .52 because that is exactly what I did. Tower had them on sale a while back for 79.99. That was cheaper than replacement parts and the darn thing pulls better than my 50sx ever did.

Dave

I just changed the bearings in my 50sx a few weeks ago and ran into the same problem. The pin is in the groove for the ring, but can be hard to see due to varnish or carbon buildup. Once you locate it and line it up with the opening in the ring, the piston will slide in easily. Good luck, Steve