could be a couple of things, first look to the gas tank vent, how much gas is in the tank, the lower the volume the longer it will run before the vacuum gets high enough to kill the pump and the second would be the pump its self is going bad. loosen the tank cap when it is running bad, and see if it will straighten up if it does you have a bad tank vent if it doesn't, then look at the fuel pressure and see if the pump is getting hot and not getting the volume of fuel to the engine.
NRTP selection Committee member
Cle Elum Ranger Dist. ORV Ranger
Build your rig to fit the trails, don't change the trails to fit your rig!