bought a 1988 Venture that had been sitting for 5 years. I had to change out the needle and seats because they were stuck. Also freed up the slides. It still only runs on choke and slow speed. Put a level tube on the float bowl. It maintains level when I try to give it throttle, and the slides start to flutter. But it cuts out. Was thinking if it was one or two bad carbs it would ramp up, just have no power. If it was the fuel pump the carb fuel level would change. I shot carb cleaner through the main jet when I had it a part. Looking for ideas