As BB says check the throttle cables. there is an adjuster on the cable near the throttle.
Check the cables are seated correctly on the carburettors mounts. Not unheard of to have the locknut come loose and the adjuster screw vibrate up and tighten the cables
Check the cables are routed correctly and check carefully at the carb end that the cable inner is not frayed on the front cable especially..An issue I have come across on bikes used over the winter and in all weathers is the throttle shaft corrodeding and sticking especiallly on number 4 carb (Right hand side ine sitting on the bike).
If this is your problem the only fix is to remove the carbs and soak the shaft are in WD40.
If all this proves ok then you will have to remove them and check the adjuster and springs are seated correctly.
Check the cables are seated correctly on the carburettors mounts. Not unheard of to have the locknut come loose and the adjuster screw vibrate up and tighten the cables
Check the cables are routed correctly and check carefully at the carb end that the cable inner is not frayed on the front cable especially..An issue I have come across on bikes used over the winter and in all weathers is the throttle shaft corrodeding and sticking especiallly on number 4 carb (Right hand side ine sitting on the bike).
If this is your problem the only fix is to remove the carbs and soak the shaft are in WD40.
If all this proves ok then you will have to remove them and check the adjuster and springs are seated correctly.