172!!! That sounds way too big. It could very possibly be leaks. I had 160 mains in mine well in Wendys too and they were still slightly too much. I run gutted stock pipes , Freak ,AI removed. Altitude plays a role as well I ride at mostly 1500 to 2000 above sea level.I also run 48 pilots but as I said in other posts I might bump that down 1 notch.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!