Had an issue with the idle rpm's on my '81 R65 the past two times I took it to work .
I used full 'choke ' for start up and the rpm's kept going up to 2500-3000 with the 'choke' off .
Have not touched the carb adjustments for about 5 years, been running great .
Took a real good look and found the right carb ' choke' stuck in the full rich position
Removed the cable and it still stayed in the full rich position.
Return spring was good, but I swapped it with the spring from the left carb and no change .
Removed the carb from the bike removed the enricher, disassembled it and found the o-ring on the shaft causing the problem, replaced the o-ring, lubed it up before reassembly and it works great now .