MOPED ARMY

take a break and try again. get a friend to try. it can be EXTREMELY frustraiting.

Here is some info I have collected from past discussions. Hope it helps

INTALLING RINGS

I just tried to change my piston rings and even after reading post and Fred’s guide I still can’t get the piston in. It keeps getting stuck in one spot

I used oil and ended up snapping one of the rings (luckily I have extras) when I foolishly tried to rotate the cylinder on….I was just wondering if there was a best way to do this or any tools that could help?! Thanks!

-Evan

you can put the piston into the cylinder from the top side and then push the piston down far enough to install the wrist pin and circlips if that’s any easier. You can make many different ring compressor designs from steel can material. And for any of you who may not already know, it’s bad form to install a ring onto the piston by putting one end in the groove and then rolling the rest of the ring into the groove. It puts a twist in the ring that causes it to bind in the groove and so the ring will not free float in the groove

Crybaby got the right idea—I’ve used a hose clamp for a ring compressor to put the piston in through the TOP of the cylinder, and pushed it down to the point where I could put in the wrist pin. Did it with hose clamps and took all of 5 seconds to slide in the piston from the top, in correct alignment even.

Slid it in from the TOP, pushed it so the skirt and wrist pin hole were showing, tapped in the wrist pin, and slid the cylinder down the studs to mate with the crankcase.

Use the screw-type hose clamps, and don’t be stingy with the oil on the cylinder bore. I used the handle of a hammer to gently tap in the piston. you drop the piston into the cylinder, then you compress the rings with the clamp, line up the clamp with the bore and tap the piston down, works almost exactly like a ring compressor for an auto piston

The trick is don’t insert the piston from the bottom—insert it from the top. get your alignment correct so your rings don’t catch in the ports, then push it out the bottom of the cylinder until the wrist pin hole is visible

Basically, what you’re doing is installing the cylinder AND piston as a unit, all at one time! Nero, the hose clamp stays stationary on top the cylinder with the rings and piston sliding in it’s inside diameter. The hose clamp doesn’t actually enter the cylinder. When you try it you’ll see