JLG X23J - X700AJ Service Manual - Manual (Page 287)

SECTION 3 - CHASSIS & TURNTABLE
3-260 – JLG Lift – 3121448
AUTO FUEL VALVE
The auto fuel valve and crankcase are connected. Vac-
uum produced by the movement of the piston and
breather function while the engine operates opens the dia-
phragm inside the fuel valve, letting fuel flow from the fuel
tube into the carburetor.
While the engine is stopped, the diaphragm closes, and
fuel flow ceases.