Yesterday we went over the main idle adjustments, and today we will delve in deeper to how to fine tune the carburetor on your ATV. Once the idle is set, it is time to make minor adjustments to the various idle positions. For the off idle to ¼ throttle, the slow jet and slow air jet are the most effective means of getting the results that you want; use a larger slow jet and smaller slow sir jet for a richer mixture, and vice-versa.
For the ¼ to ¾ throttle, raise the jet needle for a rich mixture, and vice-versa; this is accomplished by lowering the clip. The last adjustment is for a wide open throttle. The main jet is the main component for the open throttle; choose the size that offers the best performance—install a main jet that is one size larger than this to ensure engine durability. When using a lean mixture of gasoline and Evinrude XD100, your performance will increase, but you also run a risk of over-heating and piston.