Throttle Full Close Switch: Testing and Inspection

Fig. 10 Idle micro switch test connections:

Fig. 47 Idle micro switch lever. 1987 - 88 models:

Diagnostic Code 21, Idle Microswitch
1. Start engine and allow to reach normal operating temperature.
2. Disconnect microswitch electrical connector, Fig. 10, and connect an ohmmeter to switch terminals.
3. Check that ohmmeter indicates zero ohms with engine at idle.
4. Connect tachometer to engine.
5. Gradually increase engine speed from idle speed. Check that engine speed is in range of 1500 - 2400 RPM when ohmmeter indicates infinite resistance. If speed is outside of range, adjust by bending lever as shown in Fig. 47.

Fig. 12 Wide open throttle micro switch test connections:

Fig. 13 Throttle plate clearance measurement:

Fig. 14 Wide open throttle micro switch adjustment:

Diagnostic Code 21, Wide Open Throttle Microswitch
1. Remove air cleaner and carburetor.
2. Connect ohmmeter to switch as shown in Fig. 12. Resistance between terminals should be infinite.
3. Open throttle gradually until ohmmeter indicates zero ohm. Measure clearance between throttle butterfly and carburetor bore, Fig. 13. Clearance should be .29 - .33 inch (7.2 - 8.4 mm). If clearance is out of range, adjust by bending lever, Fig. 14.