fuel pump inner diaphragm probably has a rip or pinhole in it.. it's probably not the needle & seat in the carburetor because when i disconnect the fuel lines from my carburetors, even with a full tank of gas, with the engine off, there is nothing coming out of the lines unless i pull the motor over..
Just did needles and seats in mine and it fixed the prob, not as severe as yours but it still flooded. If you take the carbs to your dealer he can pressure test the needles. They should leak down no more than 1 psi per min. Mine were quite bad. Your pump should put out 2lbs at idle and about 6 at full speed, mine would not even hold 4lbs for 10 sec.
A forum community dedicated to snowmobile owners and enthusiasts. Come join the discussion about performance, racing, troubleshooting, trails, maintenance, riding tips, modifications, classifieds, gear, and more!