OlDirtyDoc is right- the problem is with your idle circuit. The idle jets are nearly impossible to get out without removing the carbs.
Check your float level first. Remove the idle screws and spray carb cleaner in there. Drain the float chambers and spray carb cleaner into the vent lines. Blow compressed air up through the float drain. Spray carb cleaner through the small holes at the throttle plate.
If this doesn't work, you'll need to remove the carbs for mechanical cleaning. 2 years is a heck of a long time for fuel to sit in the carburetors. As long as you have everything apart, upsize the idle jets one size if you are near sea-level.
Last edited by Kelly2001; 02-24-2014 at 02:48 PM.