2018 KX250F shutting down

So I just got the bike back and the problem was a loose wire or something like that, don't know exactly which one. But the guy who fixed it said the problem is 100% gone even without testing.

Edit:
So after checking the bike to see where someone touched (bike with a lot of dust), seems like the only thing is the kill switch and launch control buttons, both the lines look like they been loosened. I think same thing on the gas cables. Guess I'll never know exactly what he did (and let's hope he really fixed the problem, didn't ride yet).

Paid $160 to fix it. I know I was hustled but had no choice ):

kb228 wrote:

Post a video. Cant really give you an answer. What youre describing STILL sounds like the TPS is not correct.

Most dealership mechanics are not good mechanics. I dont trust mine more than i trust pornhub adds saying there are singles in my areas that want to hook up.

So today I got to ride the bike and it works like new!

Can't believe it was some wires not mounted correctly or too tight, I don't know exactly as the guy who fixed it didn't want to tell, but how can this cause such a problem with the bike? Tight wires / tight zipties on them? (kill switch / launch control).

Paw Paw 271 wrote:

You are looking for a .62v reading at the TPS with the throttle closed. That will increase the TPS reading at idle speed.
I know the factory shows and in fact is set lower (.48-.5v) when shipped, but that is just too lean.
You are also looking for a reading of about 5v at WOT to be sure the TPS is working correctly. The TPS reading should change ( increase) as the throttle is opened more and more. If this in not the case, the TPS is not working correctly. It could be a wiring harness issue or a bad TPS.

Also your old gas will have a big effect on the running of the bike. If the bike set that long with old gas, then you may also have a dirty fuel injector. Clean it. The old gas can also make the fuel pump filter become dirty.

Paw Paw

What's your thought on my last update? would like to hear your opinion. Might help others in future (and me).

Guess the big takeaway is when your bike dies on you, unplug the skill switch to rule out any issues there. Wiggle all the wires. Pulling in your clutch must have bumped something just enough to short it out. Very bizarre but good find by the tech.

kb228 wrote:

Guess the big takeaway is when your bike dies on you, unplug the skill switch to rule out any issues there. Wiggle all the wires. Pulling in your clutch must have bumped something just enough to short it out. Very bizarre but good find by the tech.

He took the bike for a 15 seconds ride, took a look at the bike, had a smirk and said I can fix it for you, 99%. No need for replacement parts. $160 to fix.

Can tight wires cause the issue? The kill switch and LC wires were very tight on the bars and closed tight with zipties as well.
So frustrating that the tech guy didn't want to tell me exactly what he did.
With all the dust, the only other place that might had a touch is the throttle cable attaching to the engine under the seat.

And to think the dealer wanted to order ignition coil and a fuel pump (and to check the clutch). What a joke.

kb228 wrote:

Guess the big takeaway is when your bike dies on you, unplug the skill switch to rule out any issues there. Wiggle all the wires. Pulling in your clutch must have bumped something just enough to short it out. Very bizarre but good find by the tech.

Titan777 wrote:

He took the bike for a 15 seconds ride, took a look at the bike, had a smirk and said I can fix it for you, 99%. No need for replacement parts. $160 to fix.

Can tight wires cause the issue? The kill switch and LC wires were very tight on the bars and closed tight with zipties as well.
So frustrating that the tech guy didn't want to tell me exactly what he did.
With all the dust, the only other place that might had a touch is the throttle cable attaching to the engine under the seat.

And to think the dealer wanted to order ignition coil and a fuel pump (and to check the clutch). What a joke.

$160 isnt that much. At my dealer thats 2 hours of labor. Without looking at your bike its hard to say for sure. Take his word for it and enjoy riding.

Gee, a problem with the Launch Control? What a surprise..................Too bad this wasn't suggested earlier, oh wait........

Tracktor wrote:

Gee, a problem with the Launch Control? What a surprise..................Too bad this wasn't suggested earlier, oh wait........

haha... I'm not sure it was exactly that, he didn't want to tell, just said he fixed some wires.
But I never used the launch control before. Can a tight wire do this problem?

kb228 wrote:

I think your valves are fine.

Make sure your idle is at 1800-2000 rpm. If its too low youll have issues. Theres a knob on the throttle body, turn it and it will change your idle speed. Its the “choke” knob you were referring to.

Throw in a new spark plug.

Check all your electrical connections. Clean them with electrical contact cleaner and use some dielectric grease on the plugs.

Sounds like a fuel pump or fuel injector issue to me though.

Sometimes when the temp sensors are broken it can cause that type of issue too.

If youre new, try to find an experienced mechanic to help you. Start with the cheapest stuff first. Fuel pumps are $350 and injectors are around $100. Dont want to see you throw money down the drain.

And the problem is back... not yet as bad but it will get worse each time.
Letting go of throttle and engine wants to shut off, throttle won't respond. Happens randomly.
The guy will fix it again I assume. What a weird issue. (some wire I guess).

Tracktor wrote:

Gee, a problem with the Launch Control? What a surprise..................Too bad this wasn't suggested earlier, oh wait........

Can I ride with the launch control unplugged?
I noticed when I touched the LC and Kill Switch and tried to free the wires a little bit so they won't be too tight, and the problem became worse = happened more often. Don't know if it's related or just a coincidence.

kb228 wrote:

Guess the big takeaway is when your bike dies on you, unplug the skill switch to rule out any issues there. Wiggle all the wires. Pulling in your clutch must have bumped something just enough to short it out. Very bizarre but good find by the tech.

Hey can you help me out with my last post above? Thanks!

Tracktor wrote:

Gee, a problem with the Launch Control? What a surprise..................Too bad this wasn't suggested earlier, oh wait........

So I finally know what the problem is.
It's the air temp sensor. Something with it not sitting properly/bad wires. Maybe from all the vibrations, seems like a factory issue since both my friend and I have the same issue (and also a 3rd person we know).