Sounds like youve got the chain just a bit too tight,and chainring is slightly out of round.....you want the chain to be as tight as possible w/o it binding up,should go around smoothly.To adjust that chainring,and this takes practice,loosen the chainring bolts,spin crank,then start tightening them,spin crank.Then as they get tighter find the tight spot in the chain rotation and then gently tap chainring into a postion where its not so tight.Finish tightening bolts and try it,it should be better.....it wont be perfect.May have to repeat this a few times to get it right.Your chainring may be out a whack too.....may need replaced.Sometimes there's only so much you can do,usually its close enough.In the end your chain should be fairly tight,just not so it binds up.