I have a 95 Savage LS650. All the usual carb. mods have been done, as well as the exhaust. All runs well, no backfires, etc. But I do have a problem, with full fuel tank or not with the fuel petcock in the normal run position after about 10 min. of driving it acts like it is running out of fuel, so I switch to ´reserve´ [while driving] all seems well and the fuel flow continues and I drive on. A day or so later same events as before only while fuel petcock in is still in the ´reserve´ position, so while running I turn lever to the free flow position. Fuel flows and I keep going. When I stop and check I have plenty of fuel and have only driven a total of 64 miles. Tank is clean, petcock filter is clean, fuel is new, anyone out there run into this situation?? It´s got me stumped. [by the way this is a vacume feed petcock], I´m thinking of removing the vacume diaghram from the valve to see is maybe I have a vacume problem? Also removing the gas cap to check for a blocked vent doesn´t change a thing. HELP? thanks, Les