Service Procedure: Overview

1. Replace the spark plugs with new spark plugs (NGK # BPR4ES, 0.036 in., .09mm gap).

2. Warm up the engine to normal operating temperature.

3. Turn the engine off.

4. Unplug the air-fuel ratio solenoid harness connector (Figure 1).



5. Restart engine.

6. Check "CO"%. Idle "CO%" specification:
3.0 +/- 2.0%

If out of specification, remove the idle mixture screw plug when carburetor is removed in Step 13.

7. Remove the air filter assembly.

8. Cut the carburetor harness strap and unfasten the harness clamp (Figure 2).



9. Disconnect the carburetor harness connector and remove the richer solenoid terminals as follows:

(a) Remove the yellow rear clip from the male connector (Figure 3).



(b) Remove the two richer solenoid terminals from the carburetor connector by inserting a narrow tipped screwdriver or similar tool next to the terminal. Push the locking pin away from the terminal and remove the terminal through the back of the connector (Figure 4).



10. Disconnect the vacuum hose from the vacuum piston and remove the vacuum piston from the carburetor (Figure 5). Save the vacuum piston for reinstallation in Step 16.



11. Remove the richer solenoid and discard (Figure 6).

NOTE: Adhesive was applied to the richer solenoid thread when originally installed. Therefore, tap the wrench slightly when removing.
12. Remove the carburetor from the intake manifold and empty the fuel from the float bowl.






13. While holding the carburetor with the richer solenoid port pointed downward, use the special tools to clean the adhesive from the port threads (see below).

A. Screw the tap into the richer solenoid port about 2 or 3 thread lengths (Figure 7).

B. Place the stopper attachment over the tap and with a 6mm wrench, screw the tap in until the wrench contacts the stopper attachment (Figure 8).

C. Remove the tap and stopper attachment.

CAUTION: Do not blow compressed air into the richer solenoid port to remove dust or adhesive particles.



14. Install the carburetor onto the intake manifold and carefully adjust accelerator cable.

15. Install the new richer solenoid valve as follows:

(a) Remove protector cap and apply silicone grease (or engine oil) to O-ring (Figure 9).
(b) Torque the richer solenoid valve to 15-18 ft-lbs. (2.0-2.5 kg-m)

CAUTION: Do not overtighten the richer solenoid valve.

16. Reinstall the original vacuum piston (removed in Step 10) with the new copper washer supplied in the kit.

17. Install the terminals of the new richer solenoid into the connector modified in Step 9. Reinstall the rear clip of the connector.

18. Install the new harness strap and fasten harness clamp.

19. Connect the vacuum line to the vacuum piston and then connect the carburetor harness to the carburetor.



20. Replace the ECC control unit, located under the driver's seat with the new ECC control unit (Figure 10).