Are there long lasting pistons for the 250?

Are there any aftermarket pistons for the 250 that extend the time between rebuilds? I'm not looking for more power in my bike nor do I care if I loose a little power. I am looking for a piston that I can run In my 250 that will last for a few years without having to worry about rebuilding it. Maybe someone makes a skirted piston for it or something. Does such a thing exist or do I have to continue rebuiling it every year?

No there aren't... But aftermarket forged pistons, ie. JE, CP, Wiseco are supposed to be a third stronger than stock... So Yes you will still need to rebuild every year.

Where the aftermarket pistons are nice is, I usually tear down the motor every 30 hrs for performance reasons... I measure the OD of the piston and then if it is above the service limit considerably I just re ring to restore performance and ride again. if it is below the service limit, or on it/close to, I replace the piston, rings, wrist pin and clips.

The benefit of the aftermarket one would be you could potentially get more re -ringings out of it.

So when you re reing it you hone the cylinder right?

yes so your new rings will seal correctly

Yeah, so your best bet is a JE, CP, or Wiseco 13.5 : 1 compression piston. It will also give you a little more juice and a little more reliability.

Do you have to rejet carb if you put in high comp piston????

Stock 04-05 was 12.5:1

Stock 06-07 was 12.9:1

Stock 08 was 13.1:1

The highest comp rato that you can run on pump gas is the 13.5:1 pistons, I like the JE pistons, they are $150 at the TT store.

But the highest comp ratio that is avaliable would be one of Ron Hamps JE 14.5:1 pistons, they need to be run on race gas...

Yes, Procircuit pistons are JE pistons. I have personally seen the PC pistons, and on the bottom of it, it was stamped JE, with a Part no. So save your $'s and get a JE, they are 100 less than PC.

Just wanted to chime into this thread. Could someone tell me what the stock piston compression is for an 05 crf250 and what the highest comp ratio you can get, Also does je pistons have anythingto do with pro circuit?


Boosting the compression like that won't hurt my reliability? Wouldn't it be more reliable if I got one of the new pistons you are telling me but leave it at the factory compression? If you up your compression do you need to put in stronger studs?

Thanks for all the feedback guys :applause:

I haven't found a long lasting piston like the yamaha's run... but the JE 13.5 seems to be a longer lasting piston.

Thumper racing was selling pistons with a big skirts for their BB kits... that was about the closest to long life. But no 3 ring pistons that I know of.

The reason the stock Yami's pistons run longer is because they are double ring design.


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