Well, i just got around to replacing the anemic stock petcock on my F model with a high flow Pingel race petcock. After reflecting on posts by TurboD and Trey where they state a change in performance after upgrading their petcocks, I figured i'd give it a shot myself to see if i could truly tell a difference. I had previously purchased the fuel tank adapter from from Frank (754) but never got around to installing it due to time constraints. I bought two from him, a brass one and an aluminum one and they look great. The only issue i ran into is the outlet is only 1/4" npt and all the standard, easily available Pingel petcocks are 3/8"npt. I had 3 new ones in 3/8" and was hoping i could use one to save a few bucks. I checked on Lowes website and found an adapter to step up from 1/4" npt male to 3/8" npt female threads. Upon rigging all the pieces together and check fitting it on the bike, the overall length was longer than the stock set up but i had just enough clearance to make it work. I did have to reroute the fuel lines from the carbs a little but i seems okay.
I'll be heading to the Man Cup race at the Rock tomorrow to get parked and help Trey and Bill make some test passes. I'll wait until saturday for the official time trials and race to make my passes. I'm crossing my fingers that i'll pick up some numbers with the extra fuel flow on the top end. I will admit i never noticed any signs of running out of fuel based on the "seat of the pants" feel. We will know come first time run on saturday morning if i was hurting the bikes paerformance because of fuel starvation.
I've attached some picture of the old, leaky, stock petcock and a side by side comparison picture of an old Pingel high flow petcock i had sitting around. Its identical to the new one i actually installed on the bike. Note the inlet and outlet diameters. By the way, the new one is dual outlet but i'm only using one for now and have plugged the other.