good point beechman.W out seeing abike hard to make a diagnosis w out elaborating on it.Carb syn is very important on Shees too.I didnt know this till the yamaha service writer told me.The Left carb does all the work an starts the bike then 1 it gets going the 2nd carb draws off it an provides extra fuel an enrichent for the cylinders.He went on to say ya could technically run it on 1 carb but it would run really crappy lol.