janeforbes wrote on 12/31/69 at 16:00:09:I forgot to ask. What is the purpose of the prime, what does it do?, when do you use it?
I can't find it described in my manual.
I explained it pretty well in another thread. "On" is basically automatic operation. When there's vacuum (starting or running), the fuel flows. When bike is off it doesn't.
Quote:Generally, just leave the petc0ck in the ON position. It delivers fuel only when the engine is running (or starting) so it shuts itself off automatically when you turn off your engine. Nothing special to do when starting...just leave it in the ON position all the time.
Prime is used when you run the carb completely dry either by running ON and RES empty or by physically emptying the tank (when removing it). Once you get the bike running on PRI, you can switch back to ON. Don't leave your bike in PRI while parked. This is an unresticted flow by gravity and could flood your engine with fuel (not good).
What folks usually do is run ON completely dry (you run out of gas) to see how far you can go on a tankful. Quickly switch to RES either while riding or pull off the side of the road. Then you will know how many miles you get on a tank. Probably in the 110 - 120 mile range, but it varies. Everytime you gas up, write down your mileage. When you reach 90 or 100 miles it's time to gas up.