Piston Weight. Stock vs Je

I just recived a je 12.5:1 piston and i was thinking that it might be heavier then stock but as i feel them both it feels like the stock piston is heavier. Anyone know the specs on the stock piston. Isnt she pretty.

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I would think they are trying to get the piston as close to the honda "spec weight" as they can. But it wouldnt surprise me if the honda piston was considerably heavir than the spec weight.

On mine it was only 3 grams more. :excuseme:

I just installed a CP 13.5:1. Higher dome, (obviously) stronger, (more bracing underneath near pin), wider skirt etc. All this in theory should produce a heavier piston assembly. I weighed the entire assembly (piston, rings, pin and both clips),

Stock: 352g

CP: 350g

Not a huge weight difference but considering the above, significant.

The CP piston is a thing of beauty. Every one I have installed is spot on, clearances, compression height, advertised compression ratios etc. Great product.

there was a 4.5 gram difference between the stock 04 piston i took out, and the 06 i put in.......the 06 was heavier.

How do you like the JE over the OEM piston? Do you feel a diffrence? I am going to do a top end very soon.

i havent used it yet. I wont be able to tell if its the piston or the porting making all the difference

I just put a 13.5:1 JE piston in my 05 CRF450R, I did clean up the ports, but you can definitely tell a difference! More power everywhere and I'm able to ride a gear higher in most places. What was really nice was that even though it makes more power it actually made the bike easier to ride. :excuseme:

I just put a 13.5:1 JE piston in my 05 CRF450R, I did clean up the ports, but you can definitely tell a difference! More power everywhere and I'm able to ride a gear higher in most places. What was really nice was that even though it makes more power it actually made the bike easier to ride. :excuseme:

what fuel mix do you usually use with it?

91 octane pump

A 50/50 mix of 93 pump and 110 race fuel but it runs fine on 93 pump but it just seem to have a crisper throttle with the mix. My bike is stock except for SS valves and spring kit, the 13.5:1 piston and slightly cleaned up ports. No jetting changes from the stock to this setup.

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