The PCV mod to me seems the wrong thing to do, the pcv creates a vacuum in the crankcase on the upstroke of the piston which would reduce power just like having no vent which would create excess pressure In my opinion the small hole in the airbox is to create a neutral air exchange in the crankcase? This is one mod i am not doing.
Any QUESTIONING of the efficacy of the PCV Valve Mod can get a poster BANNED from one or more motorcycle forums, Drifter! Be very careful about where you express any doubts!
Eschewing the PCV Valve Mod, you deny yourself not only the increased power allegedly available, but also the claimed additional fuel mileage, lower oil consumption, enhanced engine compression braking, and improved ring seating.
The MC Mod may indeed be a valid improvement; I simply cannot understand how the increased power is produced, given the sacrifice of 15 crankshaft degrees of valve overlap . . . cut that's jus ME!