Service manual

G420F(FE) Service Manual Chapter 2. Recommended Maintenance 16
Chapter 2. RECOMMENDED MAINTENANCE
Suggested maintenance requirements for an engine equipped with an MI-07 fuel system are contained in this
section. The operator should, however, develop a customized maintenance schedule using the requirements
listed in this section and any other requirements listed by the engine manufacturer.
General Maintenance
Test Fuel System for Leaks
• Obtain a leak check squirt bottle or pump spray
bottle.
• Fill the bottle with an approved leak check solution.
• Spray a generous amount of the solution on the
fuel system fuel lines and connections, starting at
the storage container.
• Wait approximately 15-60 seconds, then perform a
visual inspection of the fuel system. Leaks will cause
the solution to bubble.
• Listen for leaks
• Smell for LPG odor which may indicate a leak
• Repair any leaks before continuing.
• Crank the engine through several revolutions. This
will energize the fuel lock-off and allow fuel to flow to
the pressure regulator/converter. Apply additional
leak check solution to the regulator/ converter fuel
connections and housing. Repeat leak inspection as
listed above.
• Repair any fuel leaks before continuing.
Inspect Engine for Fluid Leaks
• Start the engine and allow it to reach operating
temperatures.
• Turn the engine off.
• Inspect the entire engine for oil and/or coolant
leaks.
• Repair as necessary before continuing.
Inspect Vacuum Lines and Fittings
• Visually inspect vacuum lines and fittings for
physical damage such as brittleness, cracks and
kinks. Repair/replace as required.
• Solvent or oil damage may cause vacuum lines to
become soft, resulting in a collapsed line while the
engine is running.
• If abnormally soft lines are detected, replace as
necessary.
Inspect Electrical System
• Check for loose, dirty or damaged connectors and
wires on the harness including: fuel lock-off, TMAP
sensor, O2 sensors, electronic throttle, control
relays, fuel trim valves, crank position sensor, and
cam position sensor.
• Repair and/or replace as necessary.
Inspect Foot Pedal Operation
• Verify foot pedal travel is smooth without sticking.