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Athena 280 big bore piston question.

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Hey guys I have an 07 crf250r with an Athena 280 big bore kit and i'm wondering if there is any company who makes high compression pistons that size? Don't really want to run race gas though.

Thanks.

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I haven't seen any myself but Im not sure you'd wanna do that, Im thinkin it would beat your crank like a grand canyon mule!

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Size and weight is what puts puts stress on the Rod/crank. The piston weight will stay the same no matter what compression, the shape of the top of the piston is just different. You can put a slightly higher compression piston over the one that came with the kit. What was it? 12.0 or 12.5 ? You good go up to atleast 13.0 with out any reverse effects. You can over do the compression on a bb and have a reverse effect.There's a good article in mxa on a bike they did. CP has that piston. If you don't change back you might think about a 08 cam or other brand and some porting to bring back your top end. We just put on a Cylinder works 269 kit with a CP 13.0 instead of the one it comes with.

Anyway good luck and if you go back to stock let me know if you want to sell your clyinder.

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Athena is 13.1 comp on the 280. wiseco makes a 13.5:1, I am sure you could get one from CP or JE as well. You can get higher comp like 14:1 or 14.5:1 as well but probably would need race gas.

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