have an 87 big bear 350, was running good after carb built and now it doesnt want to idle real good and seems to be running rough on occasions and seems to be running rich. pulled the plug and it was black, changed the plug but still running rough. drained the float bowl and no crud and im running ethanol free unleaded in it, the guy that rebuilt the carbg cleaned out the tank as well. Any suggestions on what to look for? Would the coil be causing any problems? Im new to this and this was my dads atv that he bought new, lost him two years ago and trying to fix it up some, any help would be greatly appreciated
