what pistion to run?

i want to bump the comp on my 93 xr650l. i see wisco 10.25:1 kit. and there is j.e. 10.5: 1 kit. what brand would you run? :thumbsup:

a very reputable shop in my area that builds bikes says - it's all a grey area. He recommended getting the wisco and he could set the compression at whatever i wanted. I trust the wisco kit a bit more, but i don't know squat about j.e.

i am thinking of doing the same - what are you thinking - 670cc's?

102.4mm wiseco - 670cc'ish i think

103mm j.e. - 671cc (xrs only has them i think rebranded as theirs)

Let us know which you go with and how you like it.

going to do the big fin or oil cooler?


Wiseco and JE are both quality pistons. I slightly prefer JE but wouldn't hesitate to use a Wiseco.

I've used both, no problems with either.

which one is lighter? lighter = faster acceleration...in therory.

Also, the closer it is to the stock weight = fewer vibes....in theory.

My bike had a JE in it when i bought it, 102.4mm is supposed to be 675cc's. I have been running a wiseco for the last 10k or so. In comparison the JE had a couple of pockets milled under the "dome" and filled with what looked like epoxy to lighten it I assume. The JE also had valve relief pockets where the wiseco didn't.

The wrist pin fit much tighter in the JE. I believe I read that wiseco bought JE a few years ago. :thumbsup:

Wiseco here with no probs after 1500 miles. Great power to boot.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now