ENGINE AND ENGINE LUBRICATION SYSTEM
A blocked tank vent port in the fuel tank cap can set up a
vacuum in the fuel tank. A fuel tank vacuum pressure
will slow fuel flow to the pump and engine.
Refer to paragraph 4.5 for fuel tank repair.
A restricted air cleaner, air induction port, or exhaust
pipe or muffler will cause a heavy black exhaust and high
Among fuel system faults that can cause the engine to
have a low power output are:
1. faulty fuel lift pump
2. clogged/dirty fuel filter
3. air in the fuel system
4. blocked fuel feed line