My ?88 Suzuki DT140, 2 stroke starts right up, runs well at low to mid-range rpm, but when you get going it will not respond to more throttle. Then all of a sudden it will really take off for a moment or two. This surge of power then returns to a bogged down state. It has fairly new spark plugs and I cleaned out the #4 carb. (lowest one), which always gets gummed up after sitting in off season. All four cylinders are running during ideal and it ideal good. Perhaps fuel pump problems? Any ideas? Thank, Jon.
