I need some info on this topic. I just sent my motor to a guy that is going to rebuild it. He said by tues or wed he will let me know the parts I need to replace. What I wanna know is if I can put a bigger piston, like to make a 300cc engine, or what not. I did see bigger piston kits in the Dennis Kirk Catolog, but I would like to know what else I need. The guy I dropped it off to is on Vacation so I couldn't ask him. Please let me know. THANKS

 

You sure you really need to go all the way up to 300? With the stock sleeve you get something like 8 overbore sizes. This allows you to have a bigger piston installed if the motor ever burns down again. If I were you, I would have the next size overbore done and have him install a wiseco fordged piston. If its already at its limit for being bored over you can have a sleeve installed. If you have the stock Honda pipe I would try to hunt down a DG pipe. The best first upgrades for a 2-stroke is to have it port and polished and install an aftermarket pipe.

This guy has many ATC250R parts.
http://stores.ebay.com/The-3-and-4-Wheeler-Shop

 

Honda used to make a factory 300 upgrade, but they are hard to find. keep an eye on ebay

 

BE very careful,, there are no pistons out there for a hondaline 300 kit for the aircooled motors,, if you are going to sleeve it you would be ok,,,,

 

That is very true, forgot about that. Wiseco may be able to make one custom if you could come up with the deminisions