LPG scooter electrics

[Julian]

I have a Chinese Vialli 50cc scooter which runs on LPG. The solenoid valve on the tank isn't opening. I can force it with a short, but this cuts out the safety feature, and it won't pass a test. The small black box that controls the solenoid has six spade contacts... two to the solenoid, a live, two that seem to have a pulsing voltage of some form, and one that disappears off towards the front of the bike but ends unconnected in a multi-connector. Any ideas how this box works, circuit diagrams,?.. I have been struggling with it for ages.
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Biscuit