Tips for installing Pistons into Cylinder when the tools are nowhere to be found??

[cancruiser]

I cant find the Merc piston ring compressor and need to get the pistons back into the cylinders on my 82 18hp. Does anyone have a tip on how it can be done without the tool and avoid breaking any of the rings?

Thanks in advance...

 

[sschefer]

Re: Tips for installing Pistons into Cylinder when the tools are nowhere to be found?

All I use is two flat blade screw drivers. I have a Jay Smith ring compressor for a 2.5 litre but I've never used it. When you use two screw drivers there less chance of the ring rotating off the pin. It takes about two tries to get the hang of it then it's a breeze.

Just slide the piston in with the rings located correctly. Put a screwdriver on each side flat then press in and lift the handles gently. She'll drop right in down to the top ring. Repeat the process and you're done. Use your thumbs to put a little pressure on the piston top. You'll get the hang of it. I sometimes use a block of wood between my chin and the piston to add a little down force.

 

[tpenfield]

Re: Tips for installing Pistons into Cylinder when the tools are nowhere to be found?

I used a technique on my Mercruiser 7.4 to re-install the pistons . . .

I used some clear plastic (like from a book report cover) and cut a piece that would fit around the piston and adequately covering the rings with plenty of room to spare. Then I got a large hose clamp (like what you would use for a dryer vent) and put it around the piston. Then I tightened the clamp enough so it compressed the rings. So the plastic band and the hose clamp act like a make-shift ring compressor.

I inserted the piston into the cylinder so that the plastic band just went into the cylinder slightly. This gives enough overlap to guide the rings into the cylinder. Then I lightly tapped the piston into the cylinder. . . . done.

 

[MercMan82]

Re: Tips for installing Pistons into Cylinder when the tools are nowhere to be found?

You can also just use your fingers. I did this with my inline 6. Pretty easy. Just go slow and if I remember right, I would get to where the chamfer is at the top of the cylinder just before the ring goes in. Have the piston already lined up with how it will go on the crankshaft. Compress with my fingers and go down slowly and turn the piston CW and CCW in very small amounts. You should feel slack guaranteeing you that the ring is positioned right with the little pin in the ring groove. Piece of cake. Btw, lube the cylinders with some 2 cycle oil and it will really help.