ive got a air fuel mixture guage in my 2.1 zvh, at normal driving it stays round to the green area ( rich ) but wen given a bit of the lead right foot it flashes between lean and rich is this right? at 140 mph it stays in the middle but slightly to the left towards lean but doesnt go into the lean area is this ok? take it at these speeds if it goes to lean then back off quickly?? is it working as it should do??