Hi all,

I am trouble shooting a problem with my fuel supply. Everything works great when in Reserve and Prime on the petcock. But when I have it in the on position, it acts as though it is starving for fuel.

Looking in the tank I am seeing what apears to be a screen/filter of some sort where the fuel lines attach at the bottom of the tank. Is that correct? I don't have manuals on the bike yet or I would look this up.

Thanks in advance.

jnosal
Yellow 99 GS500E

If you can see the in-tank filter, you might just be low on fuel.  The last gallon or so can only be accessed via the RES hose (in the RES or PRI settings).

I even get the same results with a full tank of gas.

jnosal
Yellow 99 GS500E

In that case...

The vacuum-operated diaphragm in the ON/RES/PRI petcock is fine (since RES works OK).  So you must have a blockage:

1) In the in-tank filter itself, or
2) In the passage between the in-tank-filter and the ON (short / rear) hose outlet on the tank-mounted petcock, or
3) In the ON hose itself, or
4) In the ON (front) inlet of the frame mounted ON/RES/PRI petcock.[/list:u]Here's a diagram from the Clymer manual that may help you "visualize":

Thanks I'll tear into this and see what I can find...

Just looking at the graphic, it looks like the fuel lines are in the wrong positions on the petcock which makes since after looking the innerworkings of the petcock yesterday.

jnosal
Yellow 99 GS500E