I suppose my carbs don't run right when the petcock is run on prime, the engine gets loud and the bike doesn't run right. I can't seem to find the right reasoning as to why and I don't want to know. something with the pulse must do something to the flow of fuel, maybe the float needles break loose easier on the models with the vacuum petcock/carbs.
Really, then I guess all those years I rode bikes with a manual only petcock was wrong. Putting the automatic petcock to prime is the same as turning a manual petcock to on. Do you proof read what you write cause if you did you would realize it really does not make any sense.
The diaphram on mine went bad and while I was waiting for a new one I blocked off the back side of the petcock and ran on prime only. No problems or weird noises. Maybe you have other problems
the needle has a ridge in it so it sticks, maybe I will run a drill bit through the needle jet holder.
/I saw the engire road light up last night, the needle clip positon gave it a nice toasty flame ball.
