Thank you for that. Ok most of these bikes have a vacuum system for the fuel, so your fuel tap should have "ON" - "RES" - "PRI" , that is On-reserve- prime, there is no OFF on these it only draws fuel while running, reserve is obvious as is ON but prime is for when the carbs have been emptied or run dry for some reason and it should only be used to fill the bowls then turned back to ON, try the prime position to see that fills the filter on your bike, if not then it's the wrong way round (arrow should be facing towards the carb) and that might be the cause of you fuel difficulty. Just my thoughts on it.