I would guess that None of us has a dyno ...... but air holes and jets ... even with stock muffler does feel like it
produces more power. Mine lifts the front end at faster ground speed.

guessing 3 more HP ??

 

Does that 700 pipe look like it could be modded like the 650 owners do to their stock pipes?

I am going to start storing KFX tech tips on my website, so people don't have to ask the same question over and over.

 

Yep, I'ts a little diferent inside than a 650 pipe but it still works good and what a sound. I drilled 5 1/2 inch holes and removed the spark arrestor. Opened the airbox up and jetted to 142-145, Pulls harder in the top of the mid range.