Piston problems

[howfastisit]

Hi all I just got a atm 50cc tao tao I decided to put the big bore kit on it because in a big guy and I live in Michigan. Lol I had no power going up hills. This is the first scooter I’ve owned so I’m figuring it out as I go. I Thank I have a bent rod. After I put the new piston in when I turn the engine it will only turn about a half a turn in both directions. When I took the old piston off it was scratched pretty bad on the top and bottom. This is my first post here but I will try to add pics to it as soon as I figure out how. If anyone has any idea what I broke now or missed that would help me greatly thanks in advance.

Ok update I took out the new piston and it is a lot taller then the old one and is hitting the crankshaft any ideas on how to fix?

[diynuke]

welcome to the forum


fix? well the only way to fix that is a different piston Or a spacer and you are hitting the cylinder head i guess.

could you make a picture of it?

only thing where i can think of now is a spacer


so then you need to measure the hight difference of the old and the new one and buy a spacer that is that difference
measure from the piston hole (where the piston pin goes in) to the top of the piston that distance is more important than the total height.

and check the piston skirt if its not hitting the connecting rod (the rod that connect's to your piston)
the connecting rod doesn't bend that easy so i don't think that's the issue but i can't really tell without seeing it of course ;D


you also are sure you installed the cam correctly?


and to add image's you just need to press insert image and the magic happens ;D

[90GTVert]

If the piston skirt is hitting the crank, you'd have to replace the piston or clearance the piston so it won't hit. Mark the piston and remove it from the engine before any cutting/grinding so you don't get debris in there. You don't want it to touch at BDC; needs to have a small clearance.

[howfastisit]

Thank you verry much for the help I Thank I found a shorter piston last night so I got that one and since I have a stair I’m going to shave down the one I have right now. By spring it should be the open roads for me