Carter W1 empty itself quick

[david moore]

I have the same sort of problem as mentioned here - my jeep is very slow starting after being left even for an hour or so. I can help it with a spritz of gas into the top of the carb (its a Solex in this case).
I'm wondering if the fuel cap is supposed to have an air vent? Mine doesnt. My logic is that, if sealed, there will be a partial vacuum in the tank after running - which could suck back fuel to the tank. Or is this not possible?

Or could it be that the timing is a bit off? I never know if it needs to be a shade more advanced or retarded for easier starting. I also dont know which way to turn the distributor head a little for advancing or retarding.

Comments welcome!