How to tell what replacement parts i need?

[Ch1ckenpotpie]

I have a cheep chinese 66cc motor.

I need to replace the jug/head and piston. Last piston i ordered online wasnt the right one. It was a c**t hair too tall. I dont want to make that mistake again.

This is the 2nd time ive blew out my vents. Wtf am i doing wrong? Am i just riding too long?

 

[crassius]

I believe there are only two types of piston, but am unsure how many different cylinders there are when one counts the difference in port mapping - if there is any chance of debris in the bottom end, I recommend a new motor.

What is a vent & how does it blow out?

 

[CrazyDan]

Was confused on the vents too. Pretty sure any cylinder thats made for your particular piston would work, not an expert on this though. The 2 pistons can be told apart based on pin location. A quick search of the forums should show pics of the 2 types and you can go from there.

 

[Ch1ckenpotpie]

The holes on the side walls that allow air to vent through. The holes became bigger holes.

 

[crassius]

if you mean something broke thru the cylinder walls to enlarge the transfer ports, then you'll have chunks down in bottom end - get a replacement motor rather than taking a chance of those chunks ruining a new top end

 

[Frankenstein]

I'm not even approaching this one..