Hey Y'all,
I was out on a ride and all of a sudden my bike started to not idle very well. I started to mess with the idle screw and it would rev but would be super sensitive to adjustment and would drop rev quick and die if I didnt have the screw in enough. I thought it was cable related for a second and took apart my throttle housing. It didnt seem like that was the issue so I moved to the inline filter and pulled that but it still wasnt it. I got it back to the truck and brought it home. I am trying to get this figured out this week. I have a race this weekend. I ordered a new in tank filter, spark plug, inline filter and the tps pig tail.
I pull the filter tank today and its discolored but I dont know if its bad or not.
Does anyone have what you set TPS to? I have seen some videos where they just adjust the sensor position and others that use the idle and hot start screw to make adjustments. Whats the correct way and what voltage.
Bike has about 50 hours on it.
You need to check pump pressure Both idle and tps have a measured value setting using the dealer diagnostic tool
I ordered a pump as well. Anyone got advise on checking tps? I was trying to avoid my dealer. They said $150 just to hook it up
There's plenty of videos out there explaining how to check and set TPS. It does not require dealer tools/software. Only a multimeter and a way to connect to the connector.
Most KTM's are .40v with the idle adjuster backed all the way out and then about .52 - .56 when the knobs are set to the number of clicks specified in the manual. Most people tend to run their idle a few clicks higher and also the TPS voltage a smidge higher to richen it and prevent flame out.
You filter does look a little dark, but clogged filter usually effects larger throttle openings before affecting idle.
Here's one example video.
https://youtu.be/vBviO4oldog?si=iwf3i6UG72Z0fxVw
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Yeah I have seen 2 versions one says .40 the other says .61 or something like that. I just wasn't sure if after 10 years the FI system or something had changed. Do you know anything about setting with the idle screw or cold start? I hope the TPStool.com ships quickly...
What fuel are you using? There have been issues with t4+ and some fuel pumps. Fuel pump, voltage regulator, battery, ecu, and injector can all have issues.
Did it still pull okay full throttle under load?
I swapped in take filter, inline filter and spark plug. I was able to ride and race it over the weekend with no real problems. Theres maybe a slight bog if its at idle and you just try to crack the throttle at idle but IDK if that would ever actually happen while riding. I do have a new fuel pump but I couldn't get the 3 little tabs open to get it apart. I would like to replace that soonish. Also got the tps tool and would like to check that.
Pump 91 non-e whenever I can. It seem to be doing fine at full throttle.
I just reset my TPS to .40 with the butterfly closed and about .56 idle screw in and .66 for cold start. Seems like the bike starts a lot better than before and idles a bit smoother.
So this issue came back up during a ride. I didnt replace my fuel pump because I couldnt get the plastic holder apart. Anyone got a trick for getting this apart?
I got the new fuel pump in. It started and idled fine. Rode around the block seemed fine. Went to the riding area fired it up and let it heat up. Then went for a ride. It was going good for a while but then it died. This time it wouldnt even restart like before. I tried to bump start it and it wouldnt run. It sounded like the motor was turning over but had no fuel. What would y'all next move be?
Cylinder head temp sensor Did you try starting after cool down?
yes but it wouldnt fire. Would this throw a code?
Coolant temp sensor can be bad without throwing a code. They are generally cheap and easy to replace just to check and eliminate or identify as a cause.
is there a way to test it or can you only replace with a new one?
Tried a few other items. Thought maybe a bad kill switch but I dont think its that. I jumpered the wires and it still didnt fire. I then pulled the fuel rail and fired it and it was spraying fuel fairly well. I read somewhere that the resistant was supposed to be 12v or more but mine only tested 11.5v.
Any idea what the coolant sensor resistant should be? I had another guy tell me to check valves or maybe bad rings. I really hope its not a top end at 60 hours. My last ktm 450 I got like 150 hours out of the topend and over 400 hours on the bike.
It only costs $23. I would just replace it.
I went to adjust the idle and turned the wrong knob and had to take it to my local dealer Privateer Connection for them to reset it so it would run right.
Pit Row
Replaced still wouldn't fire. FUCK me
I think I was able to set this correctly with the TPS tool but it did run well for a little before it stopped.
I had something like this a couple of months ago and couldn't figure out what the hell was wrong for months. To this day I still don't know for sure, but what I did that finally got it to run was to pull the throttle body, and clean it really well, especially the connectors. My assumption is that I had a dirty contact.
Other thing I have had issues with on KTM's is the spark plug cap cracking. Took me a long time to figure that one out and it will cause some issues as you described.
Did it seem to run hot? As in lean? In my experience KTM injectors don't like any contamination in them at all, and cleaning them is a crap shoot at best, replacing 3rd injector in my 14 KTM soon.....
some discoloration on my injector
Get a new one
Haven't got go around to doing much more. I checked the valves, all within spec. Checked grounds and everything rang out.
Well this is dumb but I got a buddies fuel pump and put it in and it seems like its working again. I think something in the fuel pump module that I rebuilt wasn't functioning.
Sorry, late to the party but agree with your findings. Probably fuel injector. I had similar issues, would back off throttle or at idle and bike would die but run ok under load. I cleaned it and it would get better for a little bit but not long. A new injector was the fix.
Fuel pump is almost the exact opposite, will idle on a stand and run ok under light throttle but dies under a strong load. You can rev it on the stand as well and since there isn’t resistance on the drivetrain it doesn’t kill the motor. That threw me off way longer than I care to admit.
Hold onto your new fuel pump if you haven’t changed it out yet. The KTM brands are pretty notorious for pump issues in the 200-300 hour mark if you keep your bikes that long.
I’ve done the rebuild on pump assemblies and bought new ones. The new ones are just a little more when you add in the costs of filters and your own time of rebuilding. I’ve found I would rather buy the whole assembly instead of repairing the old one. Plus, the hoses get brittle after sitting in fuel for several years and you will get cracks in them.
Edit: Make sure you set your idle after dialing in your TPS. I have a ‘25 350 and had a ‘16 350. They like a fast idle, like 1800-2100 rpm. It seems very fast on the stand and most people want to turn it down a little but double check your manual and leave it fast.
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