yamaha vtwin 12kw with econo throttle, when you turn the econ throttle on and use a tool it slowly revs up to the right rpm, over about 10 seconds. the dc solenoid moves instantly the engine just doesn't throttle up. also when you switch from econ to normal(full throttle) it takes 10 seconds or so for it to get up to speed. any ideas?

carb clogged, fuel not working.. if you have a fuel bowl or pump it may either be dirty or the pump is going out... or the throttle response is just slow or the timing may be off