White Bros. R-4 full system????400EX

[Kirklandrock]

anyone use the R-4 full system????? How do ya like it???? Where are the gains the most pronounced.......
THanks
Joe

[UglyMotha™]

i have it, i wouldn't run it though unless you have motor work done cause you will loose alot of bottom end and gain top cause it's got a big *** header so your goin to loose alot of backpressure