Summit 583 excessive gas consumption

[Sprucecomp]

New to site. My son bought a 1996 583 Summit, had the carbs set at local sled shop. Two problems, gas consumption is at least 30% higher than comparable sleds and you must give throttle to start, even when engine is warm. No other apparent problems with engine. Any suggestions.

 

[Dano670]

sounds to me either needle valves are leaking either by debris trapped behind valves or possible fuel pump issue like a bad diaphram letting fuel enter the pulse line .very common problem on older sleds that have been using ethanol blended fuels ,the symptoms of dissolving fuel components starts to become a real nightmare from our crappy gas .there are some additives out there now to combat the effects of blended fuel ,Ive got a1997 583 summit I use sometimes for friends to use ,awesome sled for reliability but I ended replacing all of the lines as they were getting old and causing problems out on the trail ,doesn't miss a beat now .hope this helps