just got a [build date 12 85] xt 600 running. first thing I did was a carb overhaul. the bike started up on first kick with carbs redone but pops at idle and all the time. it will stay running when warmed up. but has intermittent back fires. the 2 inlet manifolds on head are brand new as well as o rings. bike seems to have full power but pops all the time. also smells like its running lean- gets hot fast.there do not seem to be any adjust screws outside of carb except the idle wheel. any help would be appreciated. bike has 16 k miles on odo.