The new control unit is connected using a small additional harness to the same left mudguard wiring block that was connected to the air valve control unit. The control unit is connected directly to the carburetor limit switch, bypassing the mounting block. The carburetor limit switch closes to the body when the accelerator pedal is released. The addresses of the output terminals of the control unit 501.3761 are indicated in Table. 14.
Table 14
terminal no | Wire color | Address |
1 | TO | To ignition coil terminal |
2 | H | On the body |
3 | 2 | — |
4 | ABOUT | +12 V |
5 | warhead | Carburetor limit switch |
6 | joint venture | Solenoid valve carburetor |
7 | — | — |
The control unit 501.3761 must turn off the valve at a crankshaft speed of 1900 min-1 and turn on at 1700 min-1. When the accelerator pedal is depressed, i.e. when the carburetor limit switch is not closed to the body, the valve should not turn off.
Disconnect the wire from the carburetor limit switch and short the tip of this wire to the body. Connect a voltmeter to the control unit using the adapter connector. Start the engine and, gradually increasing the speed, follow the readings of the voltmeter: after starting the engine, it should show a voltage of at least 10 V, and at the moment the valve is turned off, an abrupt decrease in voltage to 0.5 V (no more).
Set the crankshaft speed within 2200-2300 min-1, disconnect the end of the wire going to the carburetor limit switch from the body, and then reconnect it to the body. When the wire is disconnected from the body, the valve should turn on, and when connected to the body, it should turn off. After turning off the valve, gradually reduce the speed until the valve turns on. The voltmeter should show an abrupt increase in voltage of at least 10 V.