Do you have an indication if it is fuel or electrical?  Fuel problems tend to happen by it surging or faultering a bit before it finally dies - electrical most often is sudden.

How long does it take for the problem to first show up?  Does it happen faster if climbing a hill or under power?

Have you tried turning the petcock to "PRIME" when this happens and see if it runs?

If it is fuel related - I would first remove the fuel line and let it flow into a gas can (PRIME POSITION) and see if the flow is steady and continuous.  If not - I would try loosening the gas cap and see if the problem is the vent in the fuel tank.  If loosening the cap does not change the flow - then it is time to take the petcock out and see if it is plugged or the diaphagm is stiff and not working.

most likely petcock, but check the wiring connectors, break and make them.

not a sticky slide, that won't kill it.

Serowbot wrote on 05/07/12 at 08:50:19:


But it takes a few tries to get it started again.  If it were just cutting out, it seems to me it would fire right back up.  ??

 
You seem to be describing some of the classical vac petcock symptoms.

Do the Serowbot test and tell us what happens.


linky linky below


Test your Petcock,.. don't just turn it to Prime..



List of Things That Tell You It May Be Raptor Time


1)  Your bike stumbles or acts like it is running out of gas when you are going over 55 mph and then when you get to the pump you can't put in 2 full gallons of gasoline.

2)  Your bike dies on you and you play bloody hell getting it to start again (you can't get any gas from your sick vac petcock no matter what you do to try to get it to start).

3)  When you get a reserve situation and roll the vac petcock toggle to Reserve, the bike continues to stumble for nearly a minute before slowly picking up some power and speed as you struggle to get to a gas station.

4)  You get all sorts of abrupt indications your carburetor is dirty or your jetting suddenly went off (and you haven't changed your exhaust system or air filter system).   Especially applies if SeaFoam, etc has NO EFFECT on your "carburetor issues" whatsoever when you try it.

5)  You smell gasoline either coming from your vac suction line, your airbox or from your oil fill port when you unscrew it (so you can sniff your oil in the sump for the scent of gasoline) because you suspect you have one of the above going on and "it may be Raptor Time".