Air/Fuel Mixture: Adjustments

Fig. 2 Spring Pin Removal.:

Adjustment of the engine idle mixture is normally not necessary. To adjust the idle mixture, the spring pin must be removed after removing the carburetor Fig. 2.

Fig. 3 Plugging Air Hoses.:

1. Disconnect the secondary air hoses from the reed valves and plug the hose Fig. 3.

Fig. 4 Checking System With Gas Analyzer.:

2. Insert an exhaust gas analyzer into the secondary air hose and plug the hose opening to prevent leakage Fig. 4.
3. Start the engine and run it at idle/
4. Measure the CO concentration.
5. Turn the mixture adjust screw and adjust the CO to the specified level (CO concentration: 1.5-2.5%).
6. If the idle speed fails to meet specification as the result of the above steps, adjust the idle speed.
7. Reconnect the secondary hoses.
8. Tap in the spring pin.