AT250es and atc250sx big bore options?

[Louis Mielke]

I'm curious has anyone looked into piston swaps for these bikes.
I'm curious if any xl/xr pistons might have the right wrist pin height and could be used for a big bore with modifications? Anyone done any research in this area?

[ScottZJ]

There was a company a couple years ago that sold a bunch of the bore kits for around 30$. I bought 8 of them and have since sold them all. I will try to find the pic of them to show you the parts numbers in hopes that you can find it somewhere.

[Louis Mielke]

I'd be real interested to know. I'd like to get a crank out of a trx300 plus a big bore to get a true 300cc. We'll see if it ever happens. Just another one of my long term ideas. lol

[SCRAMCHARGER318]

i don't believe anything else will bolt right in, or at least i've been looking for months now and haven't found anything, i talked with a company called poweroll, becuase suppesedly they used to make a 260cc kit for the es/sx, a few members on here have them, i called poweroll and they dont make them anymore, however they still have the ability to make a big bore pistn kit for the es/sx but you would have to buy at least 8 for it to be worth it to them. Maybe we could find some other es/sx owners who want the same thing and go in on it? just a thought. me personally am looking into the trx300 motor conversion, just due to fact they offer alot more performance parts for the 300, but if i could just hop up my engine i would.

1986 honda 250sx (reckless abandon)
1974 dodge dart (swamp rat)
1992 dodge ramcharger 4x4 318 magnum MPI
1995 dodge 1 ton cargo van ( trike hauler)