Xt660r
 

Hello everyone,

I've had an annoying issue lately with my motorcycle. The idle speed is going up and stays up for some time, with no no apparent reason. This can last anywhere from 5 to 20 minutes. When on-load there is no issue but his is because of the load. In neutral it just revs up stays there for a while and then comes back to normal. Any ideas?

idle speed
 

How high does it go up? mine ticks over higher now on start up because of the cold temperatures and occasionaly when the engine is wet and exposed to a cold wind this is due to the auto choke.

If it ticks over a lot higher then it could be due to air getting into the inlet system through a cracked hose/ connnecton somewhere.

As Keithy suggests, the most common causes of erratic idle speed are due to vacuum leaks allowing un-metered air into the engine. Particularly check the intake hose between throttle body and cylinder head; there have been one or two cases of premature perishing and cracking of this hose. Also examine closely the plumbing on the fast idle mechanism on the bottom of the throttle body. Under load, or on a wider throttle opening you aren't going to notice anything untoward as there is little or no vacuum in the inlet manifold. Vacuum is greatest at idle with a closed or almost closed throttle.

Other things are possibly... A frayed throttle cable inner (on either cable) which can go unnoticed and cause the throttle not to return to the stop reliably or consistently. Incorrect valve clearances, particularly tight valves, can also give rise to odd idle speeds especially when the engine is hot. When were they last checked?

Thank you for the replies. The increase in idle speed is high enough to be annoying in traffic lights. I haven't checked with the menu the actual figure. It seems to me that the engine goes in high idle mode regardless of low or high temp. Is there a case it is a failed sensor problem? Where is that external temperature sensor located? My Xt660R is 2007 model.