hi there

my xv1000 that i recently bought has a very high fuel consumption. i have cleaned the carbs and set the pilot screw again. i suspect the main jets have been enlarged for some reason as i cannot think what other part could cause such high fuel consumption (130km per tank) . its a 1981 model and the pipes have been changed to harley type pipes. also there is a misfire when i ride at high speeds and the revs are between 3000-4000kmph how ever its only when i ride on the free way at +-110kmph. could some body help shed light on this matter.