NOTE: The fuel valve is an automatic-off dia-phragm style. Fuel will flow only when the engineis being started or when it is running; however, inthe prime position, fuel will flow unrestricted to thecarburetor.
REMOVING
1. Ensure the fuel valve is not in the PRI position.
2. Remove the seat.
3. Remove the air-intake snorkel.
4. Disconnect the hose from the carburetor to the gastank at the fuel valve connection.
5. Loosen the flange clamps; then remove thecarburetor from the two carburetor boots.
6. Remove the three screws securing the throttleactuator cover (5) to the carburetor; then removethe cover. Account for the O-ring (7).
SP279
7. Disconnect the throttle cable from the actuatorarm; then loosen the outer jam nut (6) securing thethrottle cable to the carburetor body and route thecable out of the way.
SP280
8. By unscrewing the choke cable end (4), disconnectthe choke cable from the carburetor.
SP281
9. Disconnect the gas and vent hoses; then removethe carburetor.
DISASSEMBLING
1. Remove the two Phillips-head screws securing thediaphragm cover; then remove the cover, spring(1), O-ring (2), and the diaphragm (3).
SP282
2. Remove the needle holder assembly from thediaphragm. Account for a spring, spring washer,and the jet needle.
! WARNING
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3. Remove the two screws securing the primerhousing. Account for the primer diaphragmassembly (11) and spring.
SP284
4. Remove the Phillips-head screws securing thefloat chamber; then remove the chamber. Accountfor the O-ring (12).
SP285
5. Remove the float pin (13); then lift the floatassembly (14) from the carburetor. Account forthe needle valve (15).
SP286
NOTE: Note the locations of the jets, pilot screw,and holder for disassembling procedures.
SP287A
6. Secure the needle jet holder with a wrench; thenremove the main jet.
7. Remove the needle jet holder; then remove thepilot jet and the starter jet.
8. Remove and install the pilot air screw using thefollowing procedure.
A. Using a 1/8-in. drill bit with a drill-stop (1) setat 4 mm (0.16 in.) from the end, drill throughthe plug (2).
B. Thread a self-tapping screw into the plug anduse a pliers to pull the plug from the carburetorbody (4).
C. Turn the pilot screw (3) clockwise counting theturns until it is lightly seated; then remove thepilot screw accounting for a spring, washer, andO-ring.
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D. After cleaning, install the pilot screw (with anew O-ring) to the original position by turningin until it lightly seats; then turning it out thenumber of turns counted in step C.
E. Using an appropriate punch, tap a new pluginto place.
9. Unscrew and remove the idle adjustment screw.Account for the spring and washer.
ASSEMBLING
1. Screw the idle adjustment screw into thecarburetor making sure the washer and spring areproperly positioned.
2. Install the pilot jet (20). Tighten securely; theninstall the starter jet (19).
3. Install the main jet into the needle jet holder (17)and tighten securely; then install the needle jetholder assembly into the carburetor and tightensecurely.
SP287B
4. Place the float assembly (with needle valve) intoposition and secure to the carburetor with the floatpin.
NOTE: Check float arm height (A) by placing thecarburetor on its side w/float contacting the nee-dle; then measure with a caliper the height whenthe float arm is in contact with the needle valve.Float arm height should be 13 mm (0.5 in.).
SP288
5. Place the float chamber into position making surethe O-ring is properly positioned; then secure withthe Phillips-head screws.
6. Position the spring and primer diaphragmassembly (lip toward the carburetor) onto thecarburetor; then secure the assembly with theprimer housing and two screws. Tighten securely.
7. Place the jet needle, spring seat, and spring intothe piston valve; then place the assembly downinto the carburetor.
CC746
8. Place the diaphragm cover into position; thensecure with the Phillips-head screws. Tightensecurely.
AT THIS POINTPrior to assembling, the carburetor componentsshould be cleaned and inspected (see Cleaningand Inspecting Carburetor sub-section).
! CAUTIONIt is important to press down on the primerhousing until it contacts the carburetor to makesure the diaphragm lip is properly seated in thegroove in the carburetor. If the diaphragm is notproperly seated, leakage will occur.
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INSTALLING
1. Connect the gas and vent hoses onto thecarburetor.
2. Connect the choke cable by screwing the chokecable end onto the carburetor.
3. Place the throttle cable into position and secure bytightening the outer jam nut.
4. Connect the throttle cable to the actuator arm.
5. Place the throttle actuator cover into position onthe carburetor making sure the O-ring is properlypositioned; then secure with three screws.
6. Position the carburetor in the air cleaner and intakepipe boots; then secure with the clamps.
7. Connect the hose at the fuel valve connection.
8. Secure the air-intake snorkel.
9. Install the seat and make sure it locks in position.
Cleaning and Inspecting Carburetor
NOTE: Whenever a part is worn excessively,cracked, or damaged in any way, replacement isnecessary.
1. Place all metallic components in a wire basket andsubmerge in carburetor cleaner.
2. Soak for 30 minutes; then rinse with freshparts-cleaning solvent.
3. Wash all non-metallic components with soap andwater. Rinse thoroughly.
4. Dry all components with compressed air onlymaking sure all holes, orifices, and channels areunobstructed.
5. Inspect the carburetor body for cracks, nicks,stripped threads, and any other imperfections inthe casting.
6. Inspect the piston valve/diaphragm for cracks,imperfections in the casting, or cracks and tears inthe rubber.
7. Inspect float for damage.
8. Inspect gasket and O-rings for distortion, tears, ornoticeable damage.
9. Inspect tips of the jet needle, pilot screw, and theneedle valve for wear, damage, or distortion.
10. Inspect all jets for obstructions or damage.
NOTE: If the pilot jet is obstructed, the mixturewill be extremely lean at idle and part-throttle oper-ation.
11. Inspect the carburetor mounting flange for damageand tightness.
Throttle CableFree-Play
1. Check throttle cable free-play at the lever;free-play should be 3-6 mm (1/8 - 1/4 in.).
2. To adjust, slide the rubber boot away from theadjuster located near the throttle lever. Loosen thejam nut and rotate the adjuster in the appropriatedirection until proper free-play is attained. Tightenthe jam nut against the adjuster; then slide therubber boot over the adjuster.
! WARNING
When drying components with compressed air,always wear safety glasses.
! CAUTIONDO NOT place any non-metallic components inparts-cleaning solvent because damage ordeterioration will result.
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Engine RPM (Idle)
To properly adjust the idle RPM, a tachometer is nec-essary.
To adjust idle RPM, use the following procedure.
NOTE: The idle adjustment screw is located onthe right-hand side of the carburetor.
1. Start the engine and warm it up to operatingtemperature.
2. Turn the idle adjustment screw clockwise orcounterclockwise until the engine idles at1250-1350 RPM.
ATV2015A
Gas Tank
NOTE: The fuel valve is an automatic-off dia-phragm style. Fuel will flow only when the engineis being started or when it is running; however, inthe prime position, fuel will flow unrestricted to thecarburetor.
REMOVING
1. Ensure that the fuel valve is not in the PRIposition.
2. Remove the seat; then remove the gas tank.
3. Remove the body from the frame (see Section 8).
4. Disconnect the hose (1) from the carburetor to thegas tank at the tank connection; then disconnectthe vacuum hose (2).
ATV2002A
5. Remove the cap screws securing the gas tank tothe frame; then remove the air-intake snorkel (4).
SP289
6. Remove the gas tank.
! WARNING
Adjust the idle to the correct RPM. Make sure theengine is fully warm before adjusting the idle RPM.
Adjustment Screw 250/300
! WARNING
Whenever any maintenance or inspection is madeon the fuel system during which there may be fuelleakage, there should be no welding, smoking,open flames, etc., in the area.
