Also......is this a totally inconsistent problem? Like it will sometimes "rarely" idle up like that, or is it a "does it more often than not" problem?
What you need to do is see if you have any air leaks. Irradic hight idleing is either a ...........
carb synch problem
lean condition (which would be almost always consisten)
or a an air leak........which I'm thinking.
If it is an air leak, its ALMOST a sealed lead meaning that is sealing most of the time, but occassionally getting extra air causing a higher idle.
To determine if it is an air leak.....spray some carb cleaner around the carb intake boots (between the carbs and cylinders) if you notice a change in idle while spraying......you know it's cause its sucking the carb cleaner into the cylinder in that area. If so......try tightening the clamps etc to get a better seal.
FYI.......your carbs should be correctly synched prior, you should have good spark plugs and getting good spark from ignition system. (If you paid for a tune-up you should be fine with this stuff)
One sign of unsynched carbs......If you are at idle in neutral and give a twist of throtte the rpms will climb......if when you let off the throttle the tach or rpms "hang" or drop slowly or hold in certain areas....you most likely have a synch problem......if correct carb synch does nothing afterwards........you most likely have a lean problem.
When was the last time the carbs were cleaned......are the pilot jets plugged at all?
Does it have good premium gas?
Lots of things...........
Answer as much of this as possible, but first, let it warm up, adjust the idle and see it that cures it.
Ok also another thought.......I did mention above that you should be getting correct ignition spark etc.... Ignition coil failure is common with many bikes. You could have a coil that is failing almost to point of inoperation but occasionally allowing fire.....Which if your bike has seemed to run fine previously, you wont notice much difference if one cylinder is misfiring during high rpm's (these engines make alot of horse running on 3 cylinders also). Your higher idle could be a result of a failing coil occasionally firing also.
Just.....stuff like this can be easy to diagnose (in the HANDS of a GOOD tech) or can be a pain in the ass for alot of other techs. This particular situation is or can be a pain in the ass for any tech over the net without being able to test etc....himself. Simply a trial error situation by rules of a experienced person trying to explain........hope i have been or can be of help.
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