2007 S50 not firing on rear cylinder. Bike has been sitting since 2011. Emptied gas tank, cleaned and treated. Both carbs removed, cleaned and rebuilt. New air filters, spark plugs and coils and new fuel pump. Front cylinder runs and adjusts fine but rear cylinder will not fire until givin throttle at idle. The rear carb had a broken mixture screw tip stuck in the carb. Tried everything to remove it but the angle and location made it impossible to press out so had to drill it out. Would minor opening of this location cause this issue? With the new mixture screw tightened all the way down it will try to fire but pops and sputters. Or do i have another issue? I cant properly adjust all other settings or sync until it is operating properly at idle as the front carb cannot be set properly till the rear is.