125-200cc Power valve grinding for FBF135 ?

I have a FB 135 cylinder and piston on the way so hopefully there will be a bit more sting in the bikes tail
(I have gone this way as I like the idea of a properly ported head with a slight capaity increase - it was also cost effective)

Does anyone know if you need to grind the power valves for clearance on a 135 ?

Doesnt seem to have on in the kit on FBF website ( not getting much info from FBF )
Prefer to not touch them if possible
cheers

Rock Dancer,

The minimum clearance for the power valves from the piston/ring is 1mm. The stock valves tend to err on the high side so you might be "OK". The FBF kit increases the radius by 1mm so if the stock valves are at 2mm which is typical then you might just be ok. Definitely measure this to be sure as having a ring catch on a power valve isn't pretty. The closer the tolerance the better the power valve system works and the better the low-mid pull but the down side to too close is catastrophic failure and a long walk.

Walt

PS, I have talked to someone with experience with the FBF and they are designed to rip. Longevity was not the design priority so make sure your jetting is rich enough to survive the top end rip.

thanks very much Walt - said it before and I lll say it again you are a "Legend"
I will check it out
I am getting it off a guy on this website- David - second hand
The website does say that power is increased in all areaa with an emphasis on low end
so I ll see how it goes.
I do like to keep the thing pinned as much my skills allow me!
BTW Walt - Ive seen some of your GoPro footage you've sneeked onto Youtube - good on you looks like a nice place to ride.