Les 690 qui calent :une explication et un traitement (en Anglais ...)

 KTM 690 Stalling Problem Solved

Behold, a fix for the stalling ktm 690!
The ktm 690 smc (specifically 2008-10) stalling issues are well documented. For street riders, this problem can result in dangerous situations, not to mention pure aggravation. This write up is intended to help others resolve their problem with their ktm 690 smc (and perhaps 690 enduro), specifically:
Stalling on deceleration, i.e. when in motion, clutch in and throttle cut. 
Stalling at warm and/or cold idle and 
Stalling in other low rpm situations

It seems these bikes exhibit the aforementioned problems to varying degrees. Some owners experience no problem while others have been unable to resolve it. This write up is for those who have the issue and have been unable to resolve it with the myriad of proposed solutions available on the internet. I have a 2008 ktm 690 smc that no amount of mapping, throttle calibration, or tps adjustments would fix. I have found both the problem and a solution.

The problem lies with minimum air (or minimum air adjustment) and the way the ecu controls the throttle opening. If someone requests greater detail or explanation, I?ll be happy to oblige. Until then, I?ll dive into the fix. The following procedure will fix the problem. 

First, a warning. This procedure is not for the ill prepared or faint of heart. It does/will require mechanical skill, without which you will very likely create a very expensive problem for yourself. You have been warned. If, however, you are mechanically skilled, this fix should take no more than a few hours? time and will result in a fine running machine.

Overview (to be followed by specifics)
1. You will adjust the minimum air setting on your throttle body. This is something ktm does not mention, does not want you to know about, and makes it very difficult for you to do.
2. You will adjust the 3 tps settings to inform the ecu about the new position of the throttle blade. This step is very necessary or your efforts will fail.
3. Though not necessary, some minor remapping via TuneECU or some other means may be helpful.

Specifics
Remove the seat, side panels, and air box.
1. Locate the black throttle linkage cover on the left hand side of the throttle body (left side as you sit on the bike). It will be affixed with several Philips head screws and 2 headless screws. Removing the 2 headless screws will be the most difficult part of the job. Remember, ktm does not want you messing with this.
2. Remove the 2 headless screws. You will need a high quality screw extractor set for this. A cheap set will only give you problems and likely cause you to damage the throttle body. First, use a dremel tool to grind/machine a flat surface on the rounded surface of the 2 headless screws. This will prevent your drill from wandering off center. Use the appropriately sized left hand drill to drill a hole approximately 1/2 inch into the headless screws. It will not be necessary to drill all the way through the screw. Do not drill in too far as this could result in permanent irreparable damage to the throttle body. Use the matching screw extractor tool to remove the 2 screws. 
3. Remove the remaining Philips head screws. And the black cover.
4. Behind the cover, at the upper right, you will see the minimum air adjustment screw. It is an allen head setscrew and is intentionally tight in its threaded hole to prevent unwanted/unintended movement. You will turn this setscrew clockwise approximately 1/2 to 3/4 of a turn. My bike required 3/4 turn, other bikes will require slightly more or less. 
Note: this procedure will open the throttle blade in the throttle body. Too much or too little will cause unwanted results. Too little and your stalling problem will not be resolved. Too much and your FI light will flash indicating a fault. Either way, you will be repeating the procedure. I?ll get into this more in the supplemental information below.
5. Replace the black cover. Replace the headless screws with similar allen head screws.
6. Readjust the 3 tps settings per the repair manual. If you don?t have access to a repair manual, I can provide this information. 
7. This last step is not always necessary, but may improve results. Since there is now more air available to the engine at lower rpm than the existing fuel map has allowed for, a slightly richer map (specifically at or near idle) may be required. This is easily accomplished with TuneECU or similar methods.

DONE!

Supplemental information.
1. If you have not increased the minimum air sufficiently with the aforementioned setscrew, your stalling will persist.
2. If you have increased the minimum air too much, the ecu will not be able to lower the idle rpm sufficiently and will cause your FI light to flash, i.e. the ecu will be trying to close the throttle blade further than is allowed by your setscrew adjustment. 
3. Ideally, when you are finished, at warm idle, your tps voltage should be between .56 and .62 volts (there is a small amount of margin here). You can check this value with TuneECU. 
4. If the voltage is at or near .52 volts, you adjusted the minimum air too high and will need to lower it (turn the setscrew counter clockwise) and repeat the tps adjustment procedure.
5. If the voltage is significantly greater than .62 volts, you have adjusted the minimum air too low and will need to increase it (turn the setscrew clockwise) and repeat the tps adjustment procedure.