As Mark said, give the carb a clean out. With standing the float needle could be sticking. That could apply to the solenoid as well. Sometimes a light tap with a hammer or spanner helps. My C-120 liked a tap.
That forklift looks like the 12v one I have and could be finding it's self on the back of the C-120. When I get it back together. That looks manual though? Have you got any more photo's of it Nigel?
Same to you Karl. Unfortunately living where I do in the sticks, there will be no children trick or treating. Suppose I'll have to eat the sweets mesel'.
I've used both without a gasket. Depends on the condition of mating faces. The Loctite is meant to be used without. If I'm doing a cover that may need taking off, say a tappet cover, I use a gasket stuck to the cover and grease the other side.