2014 KX450f bog and hesitation at 1/4 throttle

[theDogger]

Bought a used 2014 KX450f in great shape, was vet owned with less than 20hrs on it. 

Full disclaimer this is my first DFI bike (if this was a carb bike we would not be talking) and I am lost in troubleshooting this issue and hope to get some others to help lead me down many rabbit holes

Symptoms:
+++++++++++++++++++++++++++++
1-  Bike starts cold or hot with out issue

2- Idles for about 10 secs and then starts to hesitate/blubbers and then dies

3- Starts right back up and repeats steps 1-2

4- If I can keep it running and start to ride everything seems fine but slowing down and having to start from low idle it blubbers and pops and I have to work the clutch and get the RPM's up to keep it running

5- this all seems to happen at 1/4" or less

6- Slowly rolling the throttle on up to 1/4 throttle is where it seems to be happening. Past a 1/4" throttle it is fine. Let the idle drop down and it hesitates/blubbers and dies

7 If I can keep it running after it hesitates/blubbers it will hit hard and will be fine if I stay on the throttle

++++++++++++++++++++++++++++++

- Running Chevron 93 gas
- Air Filter is clean
- No engine mods
- PC Ti-6 Full exhaust
- Black Coupler (I have tried swapping out for the other two and same issue)

[Ryankx250]

Might want to check the Throttle Position Sensor to see if it is set correctly. 

[theDogger]

How is the TPS set?
I looked at the service manual and did not see anything referring to this? I could have over looked it.

[Ryankx250]

1 hour ago, theDogger said:

How is the TPS set?
I looked at the service manual and did not see anything referring to this? I could have over looked it.

Well, I have the Kawasaki FI Calibration Kit, so I can look at it any time.  I know on the KTM Bikes, that I used the tool that these people sell https://www.tpstool.com/

But I'll be honest and tell you that I haven't adjusted mine to tell you what it's supposed to be set at.  I have a brother that has a 2012 KX450, and I'll reach out to him and see if he's adjusted his, and how he did it.

[Ryankx250]

A quick search and this was found.  I realize you don't have a stumble at WOT, but it would be a good idea to at least check out your settings

 

[theDogger]

Took these video's after changing the spark plug out. Hope it helps

On the Launch Control when the bike dies are these the diag blinks? Is that 4 short and 1 long? Does it mean anything at all?


YT Video#1

YT Video#2

 

Edited September 26, 2018 by theDogger

[jevyguy]

You need to get yourself a volt/ohm meter go through the manual and start checking everything out. I am sorry but there is no way for us to know what sort of issue you’ve got. The blinking light doesn’t mean anything...it does that every time the bike shuts off. There is an actual process to get your bike into “diagnostic mode” which I don’t know how to do. Just do a YouTube search and there is someone who could show how that’s done. In order for you to check/adjust the TPS you’ll need to get 2 different wire harnesses. One to plug into the TPS and another to plug in a 12v battery. I would check all the other things out first because I doubt you’ve got a TPS issue.

 

 

[theDogger]

6 hours ago, jevyguy said:

The blinking light doesn’t mean anything...it does that every time the bike shuts off. 

 

 

I thought that the light blinks represent codes. On my friends KX250f when he shuts it down the light comes on and then fades out. This is what I experienced before this issue. Now I get a series of flashes 4 short 1 long?

I am just going to bite the bullet and bent over an take it to the dealer?

[theDogger]

ell did the self diag test and there are no codes?

FI light just blinks steady

So radically adjusted the idle and now it idles and is not bogging....I honestly would not think that a idle adjustment would make all the difference?

Also it is me getting use to a Fuel Injected Bike and working on a different brand

Took it for a test run on the street and getting some popping in decel and still have a hesitation when rolling the throttle on. Almost like to get starved for fuel for a sec then hits?

Then when coming to a stop the idle races up and drops quickly and bike dies?

So no fault code but still have an issue at 1/4 throttle and idle now

[jevyguy]

You really should check out your TPS settings because there should be no hesitation when rolling the throttle on.

Or dying for that matter.

[theDogger]

UPDATED with poss Resolution?
++++++++++++++++++
What has been done:
------------------------------
 - New Fuel pump Filter (Quantum)
 - Cleaned Injector
 - TPS Measured: .52v
 - TPS Adjusted: .60v
So now rolling the throttle on the range is 0.60v ~ 3.68v

 - Test with all 3 couplers
 - Adjusted Valves to spec. ( we on the loose side)
 - TwinAir Tank filter
 - fresh Gas93 Chevron,

Damn!!!!Still at square one.
 - Bike fires cold or warm without issue.
 - Idols strong for a minute then the issue starts again.
 - At idol anything from 0 to 1/4 throttle blubbers but once past 1/4 throttle everything is fine I take it out on the street and start to roll the throttle on and its fine then it acts like it is starving for fuel and about dies and then it hits and starts to pull hard.

As I come to a stop the idol starts to hunt and then dies. Starts right back up and idol good for about 30 sec and then starts to hunt and then dies.

*******Well I think that I have found the problem. I have to wait and test though as I am waiting for a Pro Circuit Backfire Screen Eliminator Kit. 

So what I found was that when I put the harness back and mounted everything that the vehicle down sensor bracket was mounted incorrectly. (Backwards) Instead of facing out to the left side of the bike was mounted facing to the right side

The 2- marks on opposing side showing UPPPER with the arrow were actually at the 12 and 6 position. Reviewed the service manual and mounted the bracket correctly and this moved the sensor back above the CDI and now the 2-UPPER marks are at 3 and 9 with the arrow pointing to 12 o'clock in stead of 9 o'clock.

Could this have been the issue? Make sense.....
 

[jevyguy]

It’s slightly possible that could be the issue. The “vehicle down” sensor will kill the bike. It’s just a switch but maybe it’s bouncing on and off the switch. If that doesn’t fix it check your air intake and coolant temp sensors

[theDogger]

FIXED and Resolved
Got the bike back together and it was the Vehicle Down Sensor being mounted in the wrong orientation

This was painful, this is my first Kawi and also first EFI bike. Have been on CRF before this. What a learning experience.  

Got the bike back together and it was the Vichel Down Sensor being mounted in the wrong orientation

This was painful, this is my first Kawi and also first EFI bike. Have been CRF before this. What a learning experience.  

 

Now I can move on and start modifying the bike to my liking 

Edited October 15, 2018 by theDogger

[Ryankx250]

Thanks for posting the fix on this.