The first modification of major value done to any bike is an after market pipe.
We have tested a lot of systems and narrowed it down to the best ones below. There are some slip ons available but we do not sell them because we have not found one that improved power output. With a performance pipe, the addition of one of the jet kits and the air cleaner listed under Carburetor Accessories - 5 % to 8 % rear wheel power gains can be realized with a substantial reduction in weight.
(30 pounds lighter than stock but MUST REMOVE center stand mounts)