Originally Posted by Myfuture_yourdebt
My understanding (feel free to correct me)...
My KLR has a gravity-fed carb so obviously gravity is needed to get fuel to the carb during start-up...but isn't some amount of suction created soon after start-up because the fuel flowing through the petcock down the fuel line to the carb (acted upon by gravity) creates a siphon for fuel behind it?
There isn't any suction because the needle and seat are above the fuel level in the carb. The end of the fuel line is essentially in the air, at least whenever the needle is off the seat.