2005-2008 Honda ATV TRX500FA/FGA Fourtrax, Rubicon Factory Service Manual, Page 133Get this manual
FUEL SYSTEM For use at low altitudes, you should return the carburetor to original factory specificationsReplace the main jet with the standard main jet, and screw out the pilot screw the specified number of turns from the high altitude settingSTANDARD MAIN JET:162 TOOL: Pilot screw wrench 07KMA-MN90101 or 07KMA-MN9A100 (U.S.A.only) LOW ALTITUDE PILOT SCREW OPENING: 14 turn out from the high altitude setting Warm up the engine and adjust the idle speed at low altitude with the throttle stop screwIDLE SPEED: 1,400 100 rpm (min-1)