14
Carburetor
FUEL SYSTEM
CARBURETOR
See General Warning on page 1-2.
Before suspecting the carburetor as the cause of poor engine performance, make sure the fuel and ignition systems
are in proper operating condition. Check the following items:
• Spark plug and gap condition.
See Spark Plugs, Section 10, Page 10-11.
• Air filter element.
See Air Intake System, Section 10, Page 10-13.
• Fuel filter.
• Choke and air intake system (for restriction of air flow).
See Air Intake System, Section 10, Page 10-13.
• Fuel pump.
See the Briggs & Stratton Vanguard engine manual (CC P/N 103568101).
• Fuel lines (from fuel tank to filter to pump to carburetor).
• Exhaust system (for restrictions).
If the carburetor has failed, replace it. Procedures for inspection, removal, and installation can be found in the engine
manual.
See the Briggs & Stratton Vanguard engine manual (CC P/N 103568101).
CARBURETOR JETTING
The Briggs & Stratton Vanguard engine is equipped with a carburetor that has a fixed jet. The fixed jet does not require
adjustment. The size of the main jet is determined by the altitude where the engine will be operating. The main jet size
is set for the operating elevation of customer destination at the time of manufacture. In the event that carburetor jetting
needs to be changed, determine the proper jet size for the operating altitude.
See Main Jet Elevation Chart on page
After the proper jet size is determined, replace the main jet.
See High Altitude Jet Kit Installation Instructions
(CC P/N 103591801) that come with High Altitude Jet Kits (CC P/N 103591501, 103591601, 103591701).
No adjustment of the pilot air screw is recommended.
The following chart lists the elevation ratings for various jet sizes.
Main Jet Elevation Chart
ALTITUDE
MAIN JET PART
NUMBER
0-5000 ft.
(0-1500 m)
103549401
5000-9000 ft.
(1500-2750 m)
103549501
9000 ft. and higher
(2750 m and higher)
103549601
Page 14-2
2009-2012 XRT 950 Maintenance and Service Manual
