[algunn]

At start up when cold the engine revs to 2,000 rpm and then creeps to 3,000 then 4,000 and that's when I shut it off. You're supposed to adjust the idle when the engine is warm. I can't get to that point because it revs too much. It seems to me it's something with the "fast idle" at start up that is supposed to slow down on its own but instead speeds up, as opposed to the baseline idle speed. Anyone got a clue? Thanks!

 

[bladeracer]

At start up when cold the engine revs to 2,000 rpm and then creeps to 3,000 then 4,000 and that's when I shut it off. You're supposed to adjust the idle when the engine is warm. I can't get to that point because it revs too much. It seems to me it's something with the "fast idle" at start up that is supposed to slow down on its own but instead speeds up, as opposed to the baseline idle speed. Anyone got a clue? Thanks!

Have you tried turning the idle right down and then starting it?

 

[banana custard]

Is there anyone out there with a solution to this as my 929 has just developed the same symptoms. I did have a problem with my air temp sensor which I have sorted - I think, and was wondering if it could be a problem with the throttle bodies being out of sync???. Its only at startup when cold...hmm. It does feel a bit erratic at low speeds and at idle when warm though.

Cheers.

In the mean time I'll sync the throttle boddies...

 

[banana custard]

Synced the throttle bodies - but it hasn't solved the problem...

 

[Krzys]

I was woundering if you ever resolved your issue. I am having the same problem and can't figure it out. Thanks

 

[algunn]

I ended up taking it to the dealer. It was the idle control valve. They replaced it and it's been fine since. I think was about $200 installed.

 

[colinr06]

Hi Guys, mine has started doing the exact same thing, it has never gone up to 4000rpm before and it cant be doing a cold engine any good. Anybody got a solution or things to check. I have just fitted a power commander with a map for a stock bike but with this winter at the minute I havent ran it for a while, cant understand why it creeps to 2000 the to 3000 then to 4000 or even slightly more.

 

[Tomonet]

Hi there Guys & Girls,

I'd like to re-visit this particular question if I may as I have yet to bottom it out...

I've recently bought a 929 with a lot of miles on it (61,000) and have this very problem. On stone cold start the motor fires up first touch and idles at about 2k rpm for 10 to 15 seconds before climbing to 4k plus. I kill it at this point for obvious reasons and repeat the process. After 3 or 4 times the temperature guage starts working (not until 36 C) and at that point the revs start to drop. Once fully warm it idles happily at 1200 rpm and will start/idle normally unless left to cool completely.

I've replaced 2 of the starter valves (#3 & 4, 1 was corroded & the other was damaged) and have also replaced the wax element assembly.

Now I confess that these were good 2nd hand parts which always throws in a doubt but I don't think these parts are responsible for this problem anyway.....

All the starter valves do is to alter the amount of air which is fed into the engine via the throttle body bypass tracts - end of! On tickover the butterflys are completely closed. When you manually adjust the idle speed all you are doing is moving the starter valves backward and forward - same thing as the wax element is doing.

So the question remains...... Where does the additional air come from to enable the revs to rise as much as 5 or 6k? And once warm how is it being cut off??

Beats me!

NB. Bladeracer, I don't believe turning the manual idle control down would have any impact at all as it doesn't actually touch the starter valve assembly until the motor is fully warm.