I have a 2006 Standard with 19,500 miles. I starts up and idles fine, and always has. But recently I've noticed that when cruising for awhile at highway speeds the engine won't idle down upon releasing the throttle. In other words, I can take my hand off the throttle but the engine keeps on running at the same speed. When doing this, the engine runs smoothly and will accellerate fine - it simply won't return to idle speed upon releasing the throttle.
I've learned that switching the engine off - then back on again after a few seconds, while the bike continues in motion, will correct the problem - at least temporarily, for a few minutes or a few miles.
Less often, after cruising a low speeds at perhaps 2,000 RPM continuously for awhile, the engine will begin running very rough, misfiring as though running out of gas. Again, I've learned that switching the engine off and then back on again will clear up the rough running and it will return to running smoothly.
About 2 months ago, I had my R3 at the dealer's service department for unrelated problems. At that time they installed a new tune which they said Triumph recommended to improve engine idle, though I was not having any idle problems up until then. What this new tune did do was eliminate the "paint can rattle" my bike was experiencing.
I have cleaned my crank angle sensor and found 1 or 2 metal shavings stuck on it, but my idle problems have not improved.
Any suggestions would be greatly appreciated.