Just went through the carbs on my 88 Yamaha 90 and was wanting to find out if there was a standard adjustment on the Air Mixture Screw that is on each Carburetor. I believe it's an air mixture screw! Seems like someone told me that 2 1/4 turns out was a standard adjustment but I'm not sure.<br />Thanks in advance 
<br />herndo
<br />herndo