puch cylinder carbon cleaning

Bradford Wirt /

Hey guys,

I am dealing with a frozen puch piston. I have the head off shot some PB Blaster penetrating oil in the cylinder. I used a hammer and socket to move the piston back about an inch +. It is still stuck. I have noticed a lot of carbon build up on the cylinder walls, I saw no rust; what is the best method to remove that carbon?

The piston is still stuck, is it best to drive the piston back while the cylinder is still attached, or is it better to seperate the cylinder from the block as much as possible? I am going to try to clean up the cylinder walls and piston to reassemble and hopefully it will fire up.

Your comments are appreciated.


Re: puch cylinder carbon cleaning

I would leave the cylinder attached while gently whacking wooden dowel against the piston with a hammer. If the piston is already as far back as it will go, don't hammer it (obviously). Do you know how the engine seized? If it was seized due to overheating, parts of the piston may have melted and scored up the cylinder walls. In that event the cylinder and piston might need to be replaced outright.

Re: puch cylinder carbon cleaning

Can you turn the magneto and bring the piston back up? You probably have bottomed out the piston at the 180 degree position,so don't hit it any more. Heat the jug up and try to turn the magneto to bring the piston back up to free it some more. Keep spraying it too. If you can get the jug high enough off the rod so you can remove the wrist pin, you probably ought to get a new cylinder ,upper rod bearing and piston for it.But check the engine/tranny out first. Lower rod bearing could be shot or corroded. Ike has a lot of Puch cylinders in stock. don-ohio

Re: puch cylinder carbon cleaning

DON'S METHOD WORKS,,did it myself 2 weeks ago and my cylinder is still usable,,

Re: puch cylinder carbon cleaning

i would take the engine off the bike and sit it with the piston up and fill the cylinder with diesel and let it soak for a week. granted you aren't jammed up somewhere else.


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