Motorcycle Repair: idle rpm, intake hoses, intake tubes

Question
My Yamaha850 vintage starts up and runs. The observed symptom is that the idle rpm(~1000)increases to ~3000 as the temp increases. I feel that this is a carb. problem. Will a cleaning and kit be the fix or do the carbs need to replaced ? If it's not a carb. problem then please provide advise.
Will greatly appreciate your attention to this question.

Answer
Rick,

it is most likely a carb problem or the rubber intake
hoses leaking air. Try some wd40 or carb cleaner
around the intake tubes and see if the speed changes.
Also check for any vaccum leaks like a loose hose
or missing rubber sync cap on the intake.

-The carb linkage should be checked to see if
it is binding and the throttle cables checked as well.
Make sure there is a little free play.

-check the choke starter plungers in the carbs for
wear and/or being sticky.


-your spark plug color will indicate the fuel mixture,
charts are available here:
http://www.verrill.com/moto/sellingguide/sparkplugs/plugcolorchart.htm

-cleaning and sychronizing the carbs may be necessary
if the above doesn't help.