normal compression reading? modified motor

Jan 31, 2003
I am going to be doing the top end (piston and rings) in my 2001 KX125. The manual says usable compresssion between 199 & 150 PSI (I think).
I just got a reading from my bike that was around 167 PSI.

My question is, I have a modified bike that has been ported and has head mods. What usable range should I be in?

Also, I was reading some info on Eric Gorr's website that talked about getting different compression readings, depending if the powervalve is opened or closed. How do you know if the pv is opened or closed?

I am planning on calling the shop that did the motor work to get their figures.