Routy wrote on 08/24/09 at 07:50:56:I know all about the past petcocks that had off-on- and reserve.
But the other day I ran outta gas and was confused about the pri and res position on the petcock. And is there a mod for this to make it more trouble free ? What was wrong w/ the old off-on-res system,...it was always foolproof I thought.
"PRI" prime, for when you've run completely out of gas and need to refill the carb bowl prior to starting.
"RES" reserve, used when the main tank is empty, allows access to the bottom of the tank.
"ON" normal operation, res and on are vacuum controlled, when the engine is running, gas will flow.
Manual mod, basically, you plug 1 of the ports in the valve for off and remove the vacuum activated valve.