i have a great dane chariot jr with kaw fh500v that is not pumping fuel. I replaced filter, pump have clear gas line etc. It seems i am not getting any suction or pressure on hose that goes to valve cover. It started 2 days ago and i thought it was coil by the way it was running,,it was running fine until it gets warm(thats why i thought it was coil),,it has had small leak on top crank seal(oil coming from under flywheel),,i cleaned oil off heads to see if head gasket was damaged. cant tell. there was a brief moment when i saw gas filter fill with gas but that was short lived. what could be causing lack of pressure that draws gas for pumping action. i know the theory on how pump works. by the way,,i changed coil because it sounded like it was running on 1 cylinder,, could bad head gasket cause lack of vacuum on nipple of valve cover that goes to fuel pump. Thanks for all help. its driving me NUTS