I am new to ATV's so any help is appreciated. I was riding last night at high speeds & the engine stalled. Just like it ran out of gas. The engine will turn over but only fires intermittently. I towed it home. Checked the gas & found it low. Added gas. Spun the engine & it fired up & idled a couple of minutes then died. Fired back up & sputtered & stalled. After looking at the machine, i found a vent hose from the carb. It leaks gas when the fuel valve is turned to prime. When the valve is turned to run position, gas only comes out when the engine is spun. Do i have a diaphragm leaking somewhere?