i just rebuilt my banshee and used .80 over cylinders (66 or 68 dont really remember) + 4 stroker crank with 5 long rods full fmf gold series pipes (older version) snorkel removed stock air box and tors removed... afetr i got it all back together it was running ok but back firing, found out the tors bypass wasnt on, got it running good... i ended up spinning the sprocket off the hub and bent the hub pretty good (so it was running real good), now a week later i put it all back together and it ran great for a minute or two untill i ran outta gas. filled it up and it seems like it misfiring (popping and back firing a lil bit) and has no power!!!!! i took the carbs apart and cleaned em thinking it might have sucked stuff from the tank and still nothing. im thinking i may have water in the gas but maybe the jetting is off... the terrain i ride is between 500 1500 feet (live in the valleys of new york) around 70 80 degrees, im running 280 mains 30 pilots sound about good..... also what mixture should i use i started with 50:1 someone told me to go with 100:1 what do you think..... thanks