sounds like the carb slide diaphragm is leaking it should draw air in rom the air filter and send air under the diaphragm whcih blows it up and in turn lifts the carb slide up,also they suffer from rocker arms breaking and it will only run at low power if one of the two sets of valves isnt opening.they are a 4 valve head on the dna's
adam bike doctor
July 2009