Wiseco GP pistons

[Kenner]

I picked up some left over parts from a fellow racer for my son's yz125 and the wiseco pistons turned out to be the GP or Racer's Choice type instead of the Prolite standard ones.

What advantage or disadvantage would there be to using them? I have only used OEM or Prolite in the past. I called Wiseco and talked to their tech and he said that the lack of an intake window would alter the port timing...or I think that is what he was saying. Maybe I didn't ask the right question(s). Does the piston skirt and/or intake cuts affect port timing? Could I have a local shop cut the appropriate intake window in them for me?

Thanks.

 

[2strokerfun]

Don't know much about it except that I'd just pay for a new piston before I cut a port in a piston.

 

[whenfoxforks-ruled]

There are only a hand full of people on the planet that I would trust cutting the window, and lasting 5~8 hours of running time, and my name is not on that list! And most would ask, why not just get the correct piston Bob, "manapause" or what? Vintage Bob

 

[Kenner]

There are only a hand full of people on the planet that I would trust cutting the window, and lasting 5~8 hours of running time, and my name is not on that list! And most would ask, why not just get the correct piston Bob, "manapause" or what? Vintage Bob

Well, it is the correct part number for the 2006 YZ125 but it is a GP series instead of the Prolite. I guess i am asking if anyone runs these "as is" or are they intended to be modified for custom applications?

Kenner

 

[_JOE_]

Looks like the one you have is coated while the Pro-Lite is not. I guess it's possible there are other differences but I'd run it as is, modifying it is likely to do more harm than good.......

 

[helio lucas]

usually those pistons are for modified engines. some have the ring peg centered and only one ring.
they can be run out of the box but not to full potential.
no intake port on piston can shift the power a bit, sometimes. and i´ve seen a gp piston a bit shorter than a oem one, so effectively alter timing, nothing very radical...
:cool: