Engine Hunts And Surges - Briggs & Stratton VANGUARD M490000 Repair Manual

Step
1 Perform OBD System Check.
Are any DTCs found?
2 Perform a careful visual check.
Is a problem found?
3 Check the following fuel system components for dirt, water, or
other contaminants.
• Fuel tanks
4
• Fuel filter
• Fuel lines
• Fuel pumps
Is a problem found?
4 Verify that fuel pressure is 38-43 psi (262-296 kPa). See CHECK/
RELIEVE FUEL SYSTEM PRESSURE in SECTION 5 -
REMOVAL/INSTALLATION.
Is a problem found?
5 Check battery as follows:
• Look for loose or corroded terminals.
• Verify battery voltage is 12.2-13.5 volts.
Is a problem found?
6 Verify crankcase oil is at the correct level.
Is a problem found?
7 Verify air filter element is clean and dry.
Is a problem found?
8 Verify governor is set up properly. See Section 4 of the Intek V-
Twin Cylinder OHV Repair Manual.
Is a problem found?
9 Inspect governor link spring for damage or improper installation.
Is a problem found?
10 Disconnect governor spring, and check for binding or uneven
resistance in the governor arm travel from stop to stop.
Is a problem found?
11 Inspect governor spring and controls for damage or improper
installation.
Is a problem found?
102
ENGINE HUNTS AND SURGES
Action Yes
Go to applicable DTC Table.
Repair
Repair
Repair
Repair
Add crankcase oil.
Replace air filter element.
Repair
Repair
Repair
Repair
No
Go to step 2.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7.
Go to step 8.
Go to step 9.
Go to step 10.
Go to step 11.
Go to step 12.
Continued...