Weird Idle!?!

My Brother in law has just bought himself a 2001 650 (After having a go of my 1000 he fell in love )
However it has a strange problem, the bike can be sitting idling normally for while then the revs rise to approx 2K.....

My first reaction was sticky cables etc but no problems there. Am i going to have to strip the carbs?? or has anyone seen this before?

Any help would be great

[yorkie_chris]

The idle speed should be set with the engine warm, mines at about 1400 warm, maybe 1100 cold.

Originally Posted by yorkie_chris

The idle speed should be set with the engine warm, mines at about 1400 warm, maybe 1100 cold.

+ 1, leave the bike to warm up and then lower the idle down to its proper point.

does it go back to normal if you pull the front brake? that use to cure my RS125 when ever it started to scream on idle

[yorkie_chris]

2k is hardly screaming

Another thing that *may* cause this, is the return cable on the throttle being a wee bit loose.

Mine was doing the same thing not so long ago, and pushing the throttle closed a little more cured it, so I just tightened up the cable. Job done.

Originally Posted by yorkie_chris

2k is hardly screaming

well no, but 4k with a 30cm stubby was! mind you, it was a good scream, 2t ftw

http://www.youtube.com/watch?v=DcdSDHwGA2g

My 1 had a sticky choke cable.

Always turn the idle speed up from a lower RPM. If you have the idle set high and you want to lower it, adjust it to lower than you want and then bring it up to where you want it. That applies to many other applications too, always adjust low and bring up to the final setting.
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