Bob, regardless of its milage this is an old sled and as such could have old sled trouble like bad crankcase seals, but I would stick to the carbs a little longer.Please don't be insulted but did you really, really , clean the carb or just spray it with carb cleaner. You gotta take the following things apart {mikuni} slide, needle jet,jet needle, main jet, needle & seat, pilot screw, pilot jet and choke. clean each and every orifice and each jet completely use a powerful light and a magnifing glass if possible and spend some time on the orifices that start in the air horn of the carb. They are the ones that effect starting. If all this stuff is good, then you might want to pressure test the engine for leaks.PS. look at the piston skirts from the carb side. I had a sled that was horrible to start but ran fine and it had a broken skirt.Anyway good luck and let me know what you find. Later!
Spaceman
Mean Green Racing
Elyria, Ohio
Spaceman
Mean Green Racing
Elyria, Ohio