KTM Throttle position sensor idle

Well I screwed the pooch. Bike was fine but I have seen so many videos about they come rich from the factory and mine seemed a little spoogie so why not. Well...

I bought thevinline harness plugged in the dongle for power and my tps was showing.738. I screwed out the red idle knob all the way out but the parameters didn't change from. 738 and same for the yellow cold start high idle screw but the parameter  lowered down to .136. I set the TPS to .400 and tightened it down. Turned the red idle clockwise until I got to .500 but the paramenter didn't change from the .400. I tried several times no go. So I adjust the cold start to .600 no problem. Bike starts and idles fine. I engage the cold and the rpm's goes up too high then runs up way high turn off cold start idles fine. I start trying to adjust the idle, reset the tps and its a cluster. Right now the tps is .400, the cold start I have no clue but the rpm sounds good. Turn off the cold start and the bike dies. Won't start without throttle or cold start.

Wth happened to the idle and how do I get it back to normal. Let the flaming begin. Thanks!!

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AssangeMX
Posts
473
Joined
3/12/2024
Location
Belmarsh, CA US
11/14/2025 5:55pm

There are a bunch of youtubes that I followed.  Check em out!

11/14/2025 6:14pm
AssangeMX wrote:

There are a bunch of youtubes that I followed.  Check em out!

There are and damn near everyone is a bit different. None address the idle screw issue though. I have seen a couple that said they had to cut the idle screw spring a tad to get more adjustment but theres limited info on it.

skyrebel88
Posts
186
Joined
1/29/2015
Location
New Fairfield, CT US
11/17/2025 9:06am

I am in the same boat as you but on a 19 250sxf. A mechanic told me his process which i will write below but mine doesn't start right either still.

*screw everything out and then set TPS to 0.4-0.425. Pop cold start in and set to 0.6. Pop the cold start out and set the idle to 0.57. From there just set the idle as necessary. 

I don't think this will help, but I wanted to give you some info I was once told.  

 

11/17/2025 9:35am

I bought the service manual the other day but on my. The process is correct except after setting the .40 you need to clear the stored data by power on with wake up dongle, full throttle 3 times in under 10 seconds, fuel pump engages then power off. You then can set the other two. There are two different TPS throttle bodies out there. One the red knob effects the tps value and one that the red knob doesnt effect it.

I would recommend buying the service manual. I found alot of the older bike manuals online or like $6.00 for the download. I did the manual download from KTM for $35.00. 336 pages.

The Shop

11/18/2025 6:39pm
skyrebel88 wrote:
I am in the same boat as you but on a 19 250sxf. A mechanic told me his process which i will write below but mine...

I am in the same boat as you but on a 19 250sxf. A mechanic told me his process which i will write below but mine doesn't start right either still.

*screw everything out and then set TPS to 0.4-0.425. Pop cold start in and set to 0.6. Pop the cold start out and set the idle to 0.57. From there just set the idle as necessary. 

I don't think this will help, but I wanted to give you some info I was once told.  

 

I just got mine done. Tps. .40. Power down the bike. Power up the bike with the dongle, twist throttle wide open 3 times in under 10 seconds. Unplug dongle. Power up dongle and did the other map. THEN red idle to. 52 THEN YELLOW cold start to .62. A couple pops on the starter and she fire right. I still needed to adjust the idle and cold idle a little bit higher. My red knob would not adjust the tps without doing the full throttle thing.

 Good luck.

skyrebel88
Posts
186
Joined
1/29/2015
Location
New Fairfield, CT US
11/19/2025 4:49am

I have the TPS tool. Maybe you can attach a picture of this dongle you have. I have not used this resetting procedure you mention. I'd like to learn more about it how you use this dongle you mention. I have tried the same settings as you with decent results, but something about when the bike gets hot or warm it doesn't seem to start as easy. It will just keep turning over alot until i use the choke or it finally gives in to starting. Yesterday I set the tps to 0.4, idle at 0.45, and choke to .58 when popped in with similar results as the settings you used, but I am still struggling to find the perfect setting that fires it up as nice at it once did when it was hot. 

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