Help with getting piston into cylinder, please.

[ecumike]

Ok, I'm getting ready to replace the pistons and such.
I'm 'practicing' taking the cylinder on and off... 4 bolts and 1 tug later I've got it off... however, I'm having a tough time getting the d@mn thing back on.
I can't get the piston in the cylinder b/c of the rings.  It looks like I'm supposed to squeeze them together to slide it in? ...uhhh... anyone got any tips/tricks to getting the rings squeezed to fit the cylinder back over the piston?

[Late_Apex_Racing]

You need a piston ring compressor.  Not that expensive.  Automotive type will work if it is not too big.  It is a simple sleeve that squeezes the rings down to the size of the cylinder.  You then tap the piston down far enough to have a rings in the cylinder walls and you are done.  Try Autozone, Pep Boys, etc.

[ecumike]

So,.. here's what happened.....

[Jupiter8racing]

First
Make sure the ring gap is facing away from the port.

Next
Compress the ring with one hand while sliding the cylinder with the other. There is a little notch in the piston where the ring gap should be. make sure the ring settles in there.

Once you have it sorta on,  you can spin the crank with your hand to get con-rod and piston where you need it. You might need to wiggle the cylinder around the piston, DO NOT PUSH FROM SIDE TO SIDE ON THE CONNECTING ROD. THEY BEND VERY EASILY,

Torque the cylinder bolts in three stages using a cross pattern. The same with the head.

If you pulled the reed cages or intake maniforld I would do a leakdown test.  

Good Luck

[schpreck]

dont forget to cover the ro bolts with someting so you don't score the crank.  Once the rod is on the crank, re move these "sleves".  Remember to SIGHTLY tap the piston through the ring compressor.  Use a small sand mallot.  have fun!
-Schpreck

[ysr612]

looks like a 2 stroke there is a pin on the piston make sure it is in the gap also no need for a comp. as there is a bevel on the bottom of the cyl.

ps you need a new piston unless you are like my brother in law and tig it together on an rm and go a season like that ?????

[ecumike]

Great, thanks guys for all your help.  Yea I'm trying to take the piston off... I just figured out I need a piston pin puller... that d@mn thing's a bltch to get out.