New Piston for my CRF

[JettaJayGLS]

This is for my road race bike.

The time has come (I don't know how I made it this long without replacing em) to replace the piston/rings on my crf.

Here are my requirements:
Semi-reliable
Pump gas

That's about it.

Right now, it has an OEM piston in it. Not sure if it is the 02/03 with 11:1 compression or the 04+ 12:1 compression, but I know its oem.

My first thoughts were to just get the 04 and keep it reliable and how it is, which is great. But Smutty started talking about 13:1 kawi pistons with bigger valve reliefs, and it seems everyone and there mother are running at least 12.5:1 without problems, and I'm at a loss. Especially since just about everything I see has to do with riding dirt.

I know there's a ton of CRF knowledge on here (cough* Smutty, Chip, and Adam cough*), what are you thoughts?

Other motor work includes hot cams stage 2 cam, aftermarket crank (not sure what kind) and a port and polish.

[Paul_E_D]

O. E. M.

[Kurlon]

I agree with Paul, if reliable is part of the equation, keep it OEM.

[Paul_E_D]

I agree with Paul, if reliable is part of the equation, keep it OEM.

*gasp*

[lrrs313]

If Kurlon says not to mod it, for god sakes listen to him. And write that down its got to be a first.

[Kurlon]

If Kurlon says not to mod it, for god sakes listen to him. And write that down its got to be a first.

Let the record show, my suggestion was based on the OP's 'reliability' requirement... I have a proud hall of failure showing all sorts of very fast, very exploded bits I base this advise on. Had the OP failed to mention reliability as a concern I would have instead noted that he's running longer duration cams than stock which should lower his dynamic compression, allowing him to run a higher than stock static CR piston on pump gas safely.

[JettaJayGLS]

Let the record show, my suggestion was based on the OP's 'reliability' requirement... I have a proud hall of failure showing all sorts of very fast, very exploded bits I base this advise on. Had the OP failed to mention reliability as a concern I would have instead noted that he's running longer duration cams than stock which should lower his dynamic compression, allowing him to run a higher than stock static CR piston on pump gas safely.

Note:

Semi-reliable

[Kurlon]

Semi-reliable

Sell it, get a Husaberg single cam machine. I'll walk you through a 720cc build that'll stop all over these piddily 450cc high comp toys.

[csmutty]

Id get an aftermarket. Just make sure its below 13:1.