turn the air fuel mix screw all the way in (thats the one on the left of the carb), helps a lot on those carbs.
later you may need to adjust your carb, theres lots of guides out there already, but try that screw first. if that doesn't fix it to your content use the search bar and look up carb/carburetor tuning.
if you still can't figure out what needs to be done send me a pm and i'll try to walk you through it.
also the stock chain idlers with grubee kits are JUNK. the best one i found as a reasonably priced replacement was this one http://www.kingsmotorbikes.com/bike_...er_pulley.html
theres also better solutions to making the idlers grip if you're interested, again just send me a pm.