Mark the oil tank to be sure it is drinking so you do not burn out, any air leak to the fuel system will make a lean condition, many times the rubber ring seal in the reserve switch breaks then goes into a hole blocking the fuel flow, take it apart and new rings or a new one cost about 25bux, clean the water/fuel filter under the handlebars to get any steel gas can trash out of there so it can not go into the tiny carb filters.