OS Hyper rebuild

[earetz]

Hi Guys, Can someone give me an idea on how to get the piston ring into the sleeve whilst rebuilding? I'm sure you can buy a tool but I was wondering if anyone had any ideas. Also I notice you have to fit the piston in place before you put the sleeve in otherwise you can't get the connecting rod onto the crankcase. If I'm going about it the wrong way, please advise. Many Thanks Ed.

[george0079]

This is how I do it. There's probably another way...The trick is to get the gap in the ring lined up with the peg in the groove of the piston. Then insert the piston into the liner ( top of piston into bottom of liner) just far enough to hold the ring in place. Insert this assembly into the case just far enough to put the con rod on the crank. Once this is done, gently push/slide the liner into place. A little after-run oil or ATF on the piston and liner will help the process

[Jafa]

It certainly is important to get the ring gap over the pin

I put the piston/ring/conrod assembly into the engine and hook up to the crank

You will now note that the bottom of the sleeve has a chamfer - this helps to get over the ring
You start with the liner above the piston on an angle away from the pin
Push the sleeve over the piston, starting on the opposite side to the pin
and gradually lean forward towards towards the pin
this compresses the ring to the pin

Once you ge the nack it's real easy

[earetz]

Many Thanks, I got it together and its running fine. Happy flying!!