At about 7 hrs. our 2023 KTM 450 SXF started to randomly cut off (never on a jump thankfully). It got steadily worse over a couple of ride days. Was hard to start as well. Took it back to the dealer who thought it was probably a bad fuel pump. It turned out to be a bad wiring harness. Kudos to Magic Racing in Shelby Twp., MI for getting it figured out and fixed right away! Stuff happens sometimes.
The bike is outstanding and there are great deals on these things right now. Wish we would have waited a few months before buying, but that's how it goes sometimes. We're running the WP 6500 spring fork kit and they're excellent. Also running Xtrig ROCS triples and Xtrig PHDS bar clamps. Have swapped some other parts, but nothing that changes handling. Bike is stock other than triples/clamps and suspension.
Can you elaborate exactly where that is on the harness? Glad its all set!
Not sure. That's a pic from the dealer and I haven't had a chance to pick the bike up yet..
Ok Ty
While removing my rear shock, I pulled rear fender bolts & found a wire crimped under a 8mm fender bolt , not worn through but over time would be….
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That’s baro sensor…mine was the same..rerouted it.
it’s also the same sensor as the crank position sensor so if you want to trouble shoot and swap it real quick to see if you have an issue, it’s the same same.
Left side near battery. Pull the tank and you will be able to see the bundle squished near the frame.
Where that code/sticker is?
Just forward of the sticker. Once you pull the tank it is obvious where the tight spot for the harness is located.
DANG
Most of the harness is small gauge stranded wire and is built with several very tight bends that break internally and will create strange intermittent issues. Also the fuel filter on the 4 strokes is critical. Always check it first or replace if there are any strange issues.
*** We run a vortex ECU
Check under the tank, that has been one of the issues on a local rippers 125’s. Ktm really missed the mark on these new rides.
Is there a way to re route it or are you just stuck leaving it there until it needs to be fixed/replaced?
Well my 2023 300xc has been cutting out randomly. Tonight on a 70’ double. Scary as hell, i have no idea how i landed that endo.
i have been searching dealing with this for 2 weeks, random. I’m at the point where i just keep replacing stuff or go to the dealer. I am going to trace my harness out tomorrow. This is something that makes sense to me if its what it is by the way its acting.
I’ve heard of cases of water getting into the start/stop switch and causing issues like that. I fact I recall MXA or Dirt Bike Magazine mentioning to be careful of pressure washing the switches due to issues with water intrusion.
yes it happed to me on both my fc 250s 2023. Ive already ordered start stop switches from nihilo concepts, hope it will fix the issue
Also check the auto fuse. It is attached to front side of the battery. Mounted upside down. Over time they have a tendency to corrode with power washing.
it is a red 15 ? Amp
it is under a clear plastic cap that has a tendency to hold moisture.
I did check it, it’s clean. As far as water and corrosion I don’t wash my bike very often, I rarely run in mud, just dusty track and trails. And when I do wash it a garden hose is all it takes.
Had issues on starting, just serviced my fuel pump and in line filters....
Now I have no spark. Makes no sense since it ran before i did this.
Start stop switch is sealed so not sure how to trouble shoot.
Waiting for the battery to charge to mess with it.
Pit Row
AssangeMX there has been a problem w spark plug boots shorting out on the new models Using the 22 and earlier boot is the choice
Ran into two 2023 SXF 450 this weekend with similar issues. Both resolved.
One it was the start/stop unit that most likely had moisture in it. It bogged and died when throttle was opened and would then cut out. Took part all connections behind number plate and used compressed air to clean out moisture.
The other there was several wiring harness issues on, Copper exposed drom cables when harnessess was cut open. Bike just started cutting out and wouldn't start. Then could be good for hours/days/weeks, until now it was down to hours between failures, or even minutes in races.
Plot thickens...
So I've done inline and in tank filters. Bought the nihilo twin start stop buttons.
Bike had no spark, then cracked it with throttle open and it fired and lit up the inline spark checker.
Bike only runs with oem ecu, won't fire with vortex.
With stock ecu, I get 6 blips... tps sensor. Bizarre since when I plugged in the pigtail I had tps voltage.
Anyhow, pick up my tps pigtail and one of the pins from the tps was still in that connector!!! So tps pins must be corroded since it came out in pigtail!!!!
So I've found a couple of problems but don't know if it's the problem..
Don't wash new ktms!!!!
I don’t wash mine much, but I really don’t run in mud, actually never. When I do wash it’s just with a hose sprayer on “shower” setting and a bucket and rag.
I have many issues with my 23 concerning starting. I have replaced relays, new fuses and still at random it would decide not to start. The trick is to look at the map switch. If you hit the start button and your switch or hour meter wont light up your system has a "fault" some where and the ECU has shut everything down. I looked into things and apparently according my dealer the 23 and 24 wire harnesses are different part numbers. They are however the same harness between 23 and 24. That tells me there was clearly an issue, and with the new updated part number KTM was aware and made some changes. I am not sure as what they changed though.
Ok, another update....
I've now put new separate start stop switches, new fuel filters and new TPS and fresh calibration and back to stock ecu. New spark plug and trimmed back quarter inch of plug lead.
Bike seems to fire easily and idles well in the garage.
Fingers crossed for riding it on the weekend.
Bike ran great until it didn't 3rd moto when intermittent issues came back... still feels like fueling and spoke to xpr and a lot of fuel pumps gone bad. Ordered a new one.
@AssangeMX any update on the issues you were having?
Mine developed an intermittent "bog" recently, too. After it bogs and dies, it'll fire right back up. I checked all the connections and they seemed fine. Seems like my only option now is to start throwing parts at it... Stop Switch, Fuel Pump, Spark Plug Cap, etc.
I am not sure many are aware either but Ktm also has a update for the 23 models. It has to be done by the dealer as it needs to be hooked up to the computer. Maybe try having the update and see if that fixes anything? The update seemed to clean mine up a little. Not sure what it all entails but it's worth a try and if nothing else while it's hooked up have the dealer run a diagnostic on the system and maybe it might sense a fault.
So here is an update.
It wasn't the fuel pump, taco moto sells an inline pressure tester, it might be calibration just off, but both new and old give consistent 48 psi with no movement when twisting throttle.
Also changed the wiring harness, it didn't fix it ether.... however, ....
After the next test ride, bike was good until second moto. There is the clue.
Finally, it started giving a error code for the coolant sensor!!! So it makes sense the bike was running wierd once it was getting hot . Water can sit in that sensor after washing and corrode. So I've replaced it and it seems to run fine. Need to give a test ride, but fingers crossed.
Btw. If you use a aftermarket ecu, they don't give error codes.
My dealer has offered to hook it up to read and clear any logged issues.
Will update once I've done that
Sounds like you're getting closer, hopefully that was the fix! BTW, where is the coolant sensor located? I'll have to try that on my bike.
It's the brass part on side of cylinder, only $20 so worth trying before buying a new harness and fuel pump lol!!!
Use a bit of dielectric grease on connectors
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