Idle Speed Adjustment

Idle speed adjustment is carried out using the air screws and the idling screws.

First screw in the air screws fully, but not tightly, and back them out 1½ (US model) and 1¼ (European model) turns (S1C), or 1½ turns (S3A).

After thoroughly warming up the engine, turn the idling screws to set the idle speed to the lowest stable speed obtainable, normally between 1,200~1,300 rpm.

Listen to the exhaust noise, and place your hands behind the mufflers to feel the exhaust pressure.

If there is a variation in noise or exhaust pressure among the cylinders, re-adjust the individual idling screws to make combustion uniform.

Note: With the engine idling, turn the handlebar to either side. If handlebar movement changes idle speed, the throttle, carburetor or oil pump cables may be damaged, or the routing of the cables may be unsatisfactory.

Cable Adjustments

Carburetor Cable Adjustment

Due to stretching of the carburetor cables, the throttle valve may not respond immediately to the opening of the throttle, and the oil pump output may be too large at certain throttle openings. Check and adjust the carburetor cables periodically.

Screw in (S1C) or back out (S3A) the idling screws until the throttle valves are fully closed. Using the adjusters at the top of the carburetors, adjust all the play out of the outer sleeve of each cable, and tighten the lock nuts.

Check that the outer sleeve of each carburetor cable is seated properly in the cable adjuster.

Check the throttle grip play.

Check the oil pump adjustment.

Adjust engine idle speed.

Note: After the idle speed adjustment is made, the carburetor cables will have a small amount of play. This play is correct and should not be altered.

Oil Pump Cable Adjustment

Due to stretching of the oil pump cable, the oil pump output may be too low at certain throttle openings. Check and adjust the oil pump cable periodically.

Check to see that the mark on the oil pump lever is aligned with the corresponding mark on the oil pump lever stopper. If it is not, turn the adjusting nut to line up the two marks, and then tighten the lock nut.

Note: Make sure the banjo bolts are tight, but do not overtighten them. Any oil leakage should be corrected before riding.

After oil pump cable adjustment, check that the outer sleeve of the oil pump cable is seated properly in the cable adjusting nut.

Choke Cable Adjustment

First turn the adjuster at the lower end of each choke cable so that the choke cables have less than 1 mm (1/16 in) of play.

Then adjust the choke lever for about 4~6 mm (3/16~1/4 in) of play measured at the end of the lever.

Note: After the choke cables adjustment, check that the choke lever returns properly and that the inner cables slide smoothly. Also, check that each outer sleeve of each choke cable is seated properly in the cable adjuster and adjusting nut.