Thanks firehawk - here is my confusion:
I have a tank mounted "VACUUM OPERATED FUEL VALVE PETCOCK " (11th item from top,
http://www.scrappydogscooters.com/COMMON_PARTS.html).
The vaccum line from the fuel valve goes to the carburettor.
The fuel line goes from the fuel valve to the fuel filter and from the fuel filter goes to the carburettor.
Yes - I have verified that fuel comes out of the fuel line when the engine cranks. I removed the line from the fuel valve to the fuel filter and when the engine cranked, fuel spurted out of this...also, the fuel filter (the yellow in 2nd pic above) is full of fuel...meaning there is enough vaccum to suck air out of the fuel tank...
One thing though, the spark plug was dry throughout hundreds of attempts to start the engine - Does this mean that I need to check my float bowl (I could drain the float bowl to check presence of gasoline in the bowl without taking out the carburetor, right?)...I watched this great video (
) to educate myself.
If there is fuel in the float, then the next question to ask is if the master or primary jet is sucking the fuel out of the bowl - How do I check this?
Is there a manual test for checking enough vaccum in the carburettor?
Are there any other vaccume leaks I need to check for?