Fuelling issue help!!

[unfazed]

Bike model and year would be a great help. Check the routing of the fuel pipe, common problem on the 600 is the fuel pipe is people routing the pipe to the tank over the cross rail of the frame kinking the pipe when the tank is down. The pipe should be routed under the cross rail. On the 1000 and 600 a blocked breather in the tank could cause it, try running it with the fuel cap open. Othere issue maybe the fuel tap not fully turned on. On the 600 there is a small inline fuel filter which could be dirty enough to slow the filling of the carbs on the plastic T-piece where the fuel pipe connect to the carbs.