fuel tank petcock has to be on, prime or reserve to run a bike?

Answer 1

Should normally be in the 'on' position. This type of petcock is vacuum operated. In the 'on' position it will only supply fuel when the engine is running & the supply will automatically shut off when the engine is switched off.

The prime position allows fuel to flow when the engine is off. This is normally only used if the bike has been in storage for a long time or if the carbs have been removed for maintenance. The prime position allows you to refill the carbs before attempting to restart the engine.

If the petcock is left in prime it is a potential fire risk.

The reserve position is used when you run out of fuel. Switching to prime will normally give you about another 30 miles worth of fuel to get you to a filling station.

Edit;

Thanks Firecracker , that's exactly what I meant! I must remember to read my answers!

Answer 2

As fester said, this is a vacuum type petcock. Check to see that you have no vacuum leaks in your lines, and that there are no pinholes in your fuel lines.

Furthermore, the pickup for the On part of the petcock is higher in the tank than is reserve... When you've run the fuel low enough in the tank, you must switch to reserve to keep running. Make sure your tank is full!

Answer 3

leave it in the "on" position unless you are running out of fuel then switch to "reserve". the only reason to use the "prime" would be if the bike is not getting enough fuel while trying to start it, but you should switch it back to "on" after it cranks and runs. If you leave it in the "prime" position it will more than likely leak fuel all over the place

Answer 4

Uncle Fester is on the mark, as usual.
And I do believe he actually meant to say the Reserve position will get you further down the road.

Answer 5

You should have it on Primary. If you run out of gas for some reason, switch it over to reserve and it will usually give you 1 more gallon of gas left to get to a gas station.