1. Check the fuel shutoff system following the sequence shown:
A) Attach a tachometer to the engine;
b) Start the engine;
V) Make sure the engine runs steadily;
G) Clamp the vacuum hose of the vacuum switch;
d) Gradually increase the engine speed and check that the engine starts to run erratically;
e) Release the pinched vacuum hose and increase the engine speed again; make sure the engine runs stably;
and) With the engine idling, disconnect the solenoid valve electrical connector and check that the engine stalls/runs erratically;
h) Stop the engine and connect the electrical wire to the fuel shutoff solenoid valve. Disconnect the tachometer.
2. Check the vacuum switch.
A) Using an ohmmeter, check for continuity between the switch terminal and its body.
b) Start the engine.
V) Using an ohmmeter, check that there is no continuity between the switch terminal and its body. If abnormal, replace the switch.
3. Check the fuel cutoff solenoid valve in the primary chamber of the carburetor.