I have a 76 GL 1000 that has been recovered from storage and has been gone through. Carbs have been rebuilt 3 times as well as new plugs, points and condenser. All setting have been verified several times and yet the engine stumbles at take off. Engine idles well at 900 to 1100 rmp but when the clutch is engaged, it appears that at least one cylinder is lost and the engine will die if not given gas. I have talked to every person that might give any input on the matter. Any assistance would be appreciated.