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ajw2685
09-03-2012, 06:06 PM
I have a 2012 400X and I am looking into swapping the OEM piston out for an 11.0:1 piston. My question is with 55 hours on my machine, should I order an OEM sized piston or spend the extra money to have my cylinder bored to either a 406 or 416. I am wanting to try to just swap pistons without doing more work. I was hoping that with only 55 hours that my cylinder should still be in pretty good shape. Thoughts?

Pittsburgh400ex
09-03-2012, 06:16 PM
I'd slap a 11:1 stock bore in it. No sense boring it if not needed. You will not feel 7cc's unless y\the comprression is higher.

CJM
09-03-2012, 06:33 PM
Chances are its fine. Whatever minute wear thats on it the rings will take care of.

Drfat400ex
09-03-2012, 06:55 PM
Should be just fine, give it a hone though. Keep in mind it's more than just the piston swap to get high comp, youll need a high compression gasket kit, and hd headstuds are a good idea. Then of course higher octane fuel.

xcracer416
09-04-2012, 10:04 PM
not to burst your bubble but just a piston swap wont gain you much. put a cam and head work along with that piston to get the best gains.

i went that route several years ago when the 400ex's first came out. i thought it would be a killer with a 12:1 je and an xr cometic gasket set. man was i sadly disappointed when a bone stock engine was still hanging with me. i had sparks do some headwork with their cam and exhaust, nothing was hanging with me after that.

but i am not wanting to discourage you, more of a heads up before disappointment.