2005-2006 Honda ATV TRX500FE/FM/TM FourTrax Foreman Factory Service Manual, Page 101Get this manual
FUEL SYSTEM Remove the vacuum chamber cover, compression spring and diaphragm vacuum piston from the carburetor bodyVACUUM CHAMBER COVER
SPRING Be careful not to Turn the needle holder counterclockwise by using damage the screwdriver while pressing it in and release the diaphragm, holder flange from the vacuum pistonRemove the needle holder, spring, jet needle and washer
DIAPHRAGM VACUUM PISTON
NEEDLE HOLDER
Check the jet needle for stepped wearCheck the vacuum piston for wear or damageCheck the diaphragm for pin hole, deterioration or damageCheck the vacuum piston for smooth operation up and down in the carburetor bodyAir will leak out of the vacuum chamber if the diaphragm is damaged in any way, even with just pin holeDIAPHRAGM VACUUM PISTON SPRING