Generator fuel problem

Hi,

I have an 8KvA generator with a Jiangyang JF420 engine which I can't get started. It will run on starting gas, but it seems like no fuel is getting through. It has a Huayi H16 carburettor. Fuel is getting to the carby. I suspect problems with the anti-backfire solenoid.

Could someone explain how these solenoids are supposed to work.
Does the genny always need a working battery so that the solenoid will open when the key is turned on?
I tried putting the solenoid on a 12v battery and regardless of polarity, the needle on the solenoid extended out rather than retracting as I would have expected.
I have seen youtube videos suggesting to just grind the solenoid needle off, but I'd rather make it work as it should if I can.

Any info gratefully received

Thanks