13 250SXF Idle problem Ideas Needed

Related:
Create New Tag

1/5/2018 1:08 PM

I purchased a used 2013 KTM 250sxf early last year with 105 hours on it. The bike ran flawlessly when we first got it. Over the course of the next 5 months (now at 121 hours), the bike began to want to die when idling. This winter I decided to have the engine rebuilt completely. So I took the engine to the local KTM shop with all new OEM parts for the rebuild (Piston kit, connection rod kit, all new bearings, gaskets, valve kit, etc...) However, after the engine rebuild and installation, the problem is still there.

I also replaced the filter attached to the fuel pump inside the tank. Replaced the tiny inline filter that comes from the tank to the throttle body as well.

The shop pulled the injector and cleaned it and checked the spray and said it was working fine.

Any suggestions or ideas would be appreciated.

Thanks

|

1/5/2018 2:20 PM

Idle adjusted?
TPS checked and or reset?
Fuel pump tested?

Paw Paw

|

1/5/2018 2:42 PM
Edited Date/Time: 1/5/2018 2:44 PM

Idle/choke does nothing. Kinda strange. TPS checked and is also good.

Choke works when pulled out. Idle doesn’t do much.

Never checked the fuel pump output. Never thought of that. Thanks

|

1/5/2018 5:54 PM

Check you coil..

|

" If I spent as much time as you guys do, tapping away at your semen stained keyboards... I would have all the answers too!

1/5/2018 6:04 PM
Edited Date/Time: 1/5/2018 6:04 PM

You do understand that the idle adjustment is located under the throttle body throttle cables on the other side of the throttle body from the choke, right?

Paw Paw

|

1/5/2018 7:05 PM
Edited Date/Time: 1/5/2018 7:26 PM

LOL, yes Paw Paw... I read my post after I posted it and realized how it sounded. Just trying to do it from my phone and didn’t feel like clarifying. My bad.

The idle doesn’t do much. When the choke is pulled out, it stays running. Would that eliminate the fuel pump being bad?

Knobby, Would the coil only kill it at idle? Once you get the bike going it runs fine until you pull in the clutch. Then it dies. Meaning when I am riding it, if I hold the clutch in too long without revving the engine, it will die.

Just trying to figure out what to buy to fix it without spending a ton in parts for trial and error.

|

1/6/2018 8:46 AM

Paw Paw 271 wrote:

Idle adjusted?
TPS checked and or reset?
Fuel pump tested?

Paw Paw

So I called back out to the shop, the only thing they have truly done to it was back flushed the injector and cleaned it and verified the tps was working. They have not adjusted the TPS yet. Somehow they had to drill out a screw that holds the injector in. So they are waiting on that before going further.

I think after they get the Injector squared away, I will just pick up the bike and figure it out from there. I ordered the cable to adjust the TPS. If that don’t fix it, I will probably swap out the fuel pump. If that don’t work, guessing I will try to get the ECU remapped? Maybe there is a bug in that?

What really bugs me is the fact the idle adjustment screw doesn’t seem to do anything. Is that a symptom of something else? Or is there anyway the adjuster could be bad?

|

1/6/2018 10:49 PM

Paw Paw 271 wrote:

Idle adjusted?
TPS checked and or reset?
Fuel pump tested?

Paw Paw

brywil73 wrote:

So I called back out to the shop, the only thing they have truly done to it was back flushed the injector and cleaned it and verified the tps was working. They have not adjusted the TPS yet. Somehow they had to drill out a screw that holds the injector in. So they are waiting on that before going further.

I think after they get the Injector squared away, I will just pick up the bike and figure it out from there. I ordered the cable to adjust the TPS. If that don’t fix it, I will probably swap out the fuel pump. If that don’t work, guessing I will try to get the ECU remapped? Maybe there is a bug in that?

What really bugs me is the fact the idle adjustment screw doesn’t seem to do anything. Is that a symptom of something else? Or is there anyway the adjuster could be bad?

I believe the idle adjustment will also change your TPS setting. Once you check your TPS, that could be the answer. Maybe there’s some reason your TPS is super far off?

Is the spark plug new?

|

1/7/2018 10:14 AM

Paw Paw 271 wrote:

Idle adjusted?
TPS checked and or reset?
Fuel pump tested?

Paw Paw

brywil73 wrote:

So I called back out to the shop, the only thing they have truly done to it was back flushed the injector and cleaned it and verified the tps was working. They have not adjusted the TPS yet. Somehow they had to drill out a screw that holds the injector in. So they are waiting on that before going further.

I think after they get the Injector squared away, I will just pick up the bike and figure it out from there. I ordered the cable to adjust the TPS. If that don’t fix it, I will probably swap out the fuel pump. If that don’t work, guessing I will try to get the ECU remapped? Maybe there is a bug in that?

What really bugs me is the fact the idle adjustment screw doesn’t seem to do anything. Is that a symptom of something else? Or is there anyway the adjuster could be bad?

CarlinoJoeVideo wrote:

I believe the idle adjustment will also change your TPS setting. Once you check your TPS, that could be the answer. Maybe there’s some reason your TPS is super far off?

Is the spark plug new?

I never would have thought the TPS would be changed by altering the idle. To be honest, I do not know that much about fuel injection. Still learning. I just got notice my TPS adjustment wires have shipped so, I will adjust it when I get them in.

As far as the plug goes, I did use a new one. I did think about checking that again. If the TPS don’t work, I will check the plug before going further.

From the way it sounds, the TPS just needs adjusted. Fingers crossed. I will post either way if it works or more troubleshooting is needed.

Thanks for the response.

|

1/8/2018 12:08 PM

Idle must be backed off all the way to adjust your TPS. stock setting on 2013 is .62

|

1/8/2018 12:17 PM

RCF wrote:

Idle must be backed off all the way to adjust your TPS. stock setting on 2013 is .62

Thanks for the tip on that. I had found the setting for the tps but I didn’t know the idle had to be backed all the way out. Would have screwed that up for sure.

|

1/15/2018 1:02 PM

Just an update on this issue. Finally figured it out.

There are two “O” rings for the injector. One of them actually went bad. Replaced the O ring and it is running great. Plus the idle adjustment works. I have no idea the correlation with the o ring and the idle adjustment. But apparantly there is one.

Do want to thank everyone that piped in on possible causes.

Thanks

|

1/15/2018 2:37 PM

brywil73 wrote:

Just an update on this issue. Finally figured it out.

There are two “O” rings for the injector. One of them actually went bad. Replaced the O ring and it is running great. Plus the idle adjustment works. I have no idea the correlation with the o ring and the idle adjustment. But apparantly there is one.

Do want to thank everyone that piped in on possible causes.

Thanks

vacuum leak more than likely.

|

2018 KTM 250sx
Instagram CamaroAJ

1/25/2018 7:11 PM

UGH!!! This bike is beginning to really annoy me! So the problem was not fixed by the O rings. Went to just start it up again today and the problem came back. However this time, I was ready for it. I noticed a small exhaust leak from condensation coming out of the silencer at the front. So I replaced the O rings on the exhaust (must not have sealed great when I repacked it). Then I went ahead and adjusted the TPS. Made sure it was set as close to .62 as possible. With the idle backed all the way out. The good news, it runs... the bad news... I can’t get it to idle in a good range.

If I turn the idle screw in far enough to where it stays running, it idles high. If I back it out a fraction of a turn, it dies.

I did have the throttle cables replaced. Could those be set up wrong? Think I need to adjust the tps one way or the other? Other than those two things, I am at a loss. You all have been pretty spot on with everything so far, so I figured I would run it past you guys again.

Any help is appreciated.

|

2/24/2018 6:52 AM

Just a quick update. For those who may come across this problem.

Everything on the bike checked out ok. So... The shop finally started swapping parts off of a new bike and when they swapped the tank, the bike ran great. So even though the pressure was fine when they checked the fuel pump, it was still causing the bike to idle high and not run at idle speed.

Hopefully, it is fixed now.

|