Popriv

OS .50SX ring - replaced the bearings, piston is in and attached to the drive. I cannot get the cylinder sleeve to fit over the piston ring..

Any tips?

steve

mighty9

My Feedback: (10)

make sure the ring gaps are centered over the pin in the groove...

spaceworm

With the ring as above, aligned with the pin, compress the ring with a small gear type hose clamp just tight enough to hold the ring in the groove, but so you can slide the piston/ring out of the clamp into the sleeve. Good luck.

Regards,

Richard

Popriv

Yes, spin ring slightly and it slipped on. VERY tight, cant turn over by hand.. hope thats normal?

steve

Popriv

Doesnt seem right piston seems to bind in sleeve. ?

spaceworm

I would say not normal. Make sure the ring ends are aligned with the pin in the piston. Make sure the rings ends have not caught in a port. Make sure you have the right rings. Was there a lot of crud in the ring groove? If so did you clean it all out before you put the new ring in? Did the ring feel "right" in the groove, without binding, but not loose? Some rings have a top and a bottom, if yours did was it put in as indicated? Did you put some assembly lube on the ring, piston and sleeve before assembling? Good luck.

Regards,

Richard

w8ye

My Feedback: (16)

You have already caught the ring end in a port

freakingfast

My Feedback: (3)

Good chance the ring and maybe the sleeve is toast. Next time, try a dry run outside the case.....gently. You must index the ring ends with the pin in the piston ring groove. The piston can go in two ways, but one is the right way so that the ring ends don't catch ports, carbon stains on the piston can give you clues to where the exhaust port should be if you didn't take note at dis-assembly. If the ring ends catch a port, use wood or plastic(not metal) to push the ring back into the groove....unless you managed to put the pin behind it

See the big red warning posted under your bearing noise post.

Popriv

Took it apart and reassembled. smooth now.

freakingfast

My Feedback: (3)

Rings are frail and can distort if mishandled. Check if the compression is as before, than run it.

Popriv

Should have waited for your replys before I forced it together,, Duh.. Got everything apart and reassembled properly. Ring and sleeve looked ok but ?????

I mounted on a stand this morning and it started... Bearing noise is now gone, only question is did I score up the sleeve? I'll put it back on the plane and try flying it...

thanks for your help. learned allot.

Steve

ArcticCatRider

My Feedback: (6)

If you scored it, then you scored it. If it runs and makes full power....I wouldn't worry about it. Run it!

Even if you had happened to scuff or ding a port, it can almost always be corrected with some emery cloth. These engines can run with a lot more scars than they're given credit

Popriv

I put in back in the plane and started it up, no more bearing noise and seems to be running fine..plenty of power...

should be fine.

Thanks again for the help...

freakingfast

My Feedback: (3)

Good!...this next part is very crucial, so listen good....
Don't worry about it any more and have fun.

kenhiraihnl

I don't own a .55, but isn't there an arrow on the top of the piston that points to the exhaust port? Some of my other OS engines have the arrow.