Engine Stutter / Pause / Stall

[guernsey70]

Hi guys,

I haven't posted in a while, but lovin the new forum format!

I've just traded in my old Tracer for a Tracer GT, but seem to be having an issue with the quick shifter (or something electronic!?) cutting power to the engine momentarily .  Basically, when using the clutch from 2nd to 3rd at about 30-40mph the engine cuts out for a split second, which feels like a stall / stutter.

I've had a new quick shifter fitted, but that hasn't fixed the problem

Has anyone else experienced this / got any insight?

Thanks

G70

[koth442]

Are you using the clutch with the quick shifter? I've never used a QS but from my understanding the QS cuts ignition for a split second allowing the clutchless upshift. Hopefully someone with more experience will chime in soon.

[guernsey70]

Thanks. 

It only stutters / stall when I'm going through the gears with the clutch only, so not using / touching the QS.   

[gv550]

My GT does the same thing, I've determined it is operator error.

The switches in the clutch lever and shift lever are sensitive, and I was inadvertently touching the shift lever after shifting which kills the engine. I shortened my shift linkage a bit to slightly raise the lever from my foot and just pay more attention to getting my boot away from the shift lever after completing each shift. And using the quick shifter more often reduces the problem too, and more fun!

[guernsey70]

I will double check where my foot is on the shift lever to make sure I'm not touching it, but I would have thought that it would happen a lot if that was the case.......  

I hear you about it being more fun, but hard to use sometimes whilst weaving your way through the busy streets on London!

 

[bugie]

Make sure the bike is idling at the correct speed. My old GSR600 used to do this when i pull in the clutch when the idle was too low 

[Laineymcvlog]

Guys did anyone get to the bottom of this. I've had it happen at least 50 times in 2 months. 

 

Here's a video 

 

[johnmark101]

10 hours ago, Laineymcvlog said:

Guys did anyone get to the bottom of this. I've had it happen at least 50 times in 2 months. 

 

Here's a video 

 

That would be very annoying.  It sounds like the very brief pulse of cutting power which would occur when using the quick shifter.  Obviously that is not what you were doing in the video.

I would check the shift linkage first.  See what amount of free play it should have per the service manual and make sure yours is correct.  If it were too tight maybe it is causing the issue.    

Edited March 20, 2020 by johnmark101

[angusmcoz]

12 hours ago, Laineymcvlog said:

Guys did anyone get to the bottom of this. I've had it happen at least 50 times in 2 months. 

 

Here's a video 

 

You could try shutting off the quick shift feature and see if that corrects the problem. Under the topic Quick Shifter in Tracer 900 GT Discussions, Tracerracer posted the following instructions that worked for me. "push the shift lever up, turn ignition key on, wait 10sec, release the shift lever - QS will be disabled/enabled. no need to unplug something." Important to maintain pressure up on the shift lever the whole 10 sec.

[Laineymcvlog]

Hey dude. I did exactly that and has no issues for 7 weeks. I turned it back on again and a week or 2 later it occurred again... Because it didn't do it instantly...I'm really not sure what's causing it.

[coachluciano]

Clutch switch when engaged should disable the QSer.  It sound like yours is not.  Bike thinks you want to QS and is retarding the timing - while you are clutch shifting - I went through this is my HealTech QSer. 

[mike]

Lainemcvlog, did you ever find the cause? If not, has turning off the QS solved the issue?

[Laineymcvlog]

On 8/7/2020 at 2:29 PM, mike said:

Lainemcvlog, did you ever find the cause? If not, has turning off the QS solved the issue?

Yes. Quick shifter replaced under warranty.  No issues for 4 month's. Knew it was a faulty quickshifter man

[pgeldz]

Well, add me to the list with the same exact problem.

2019 Tracer 900 GT.  11,000 trouble free miles.  Flashed by Ivan, and also have a Rapid Bike RACE with auto blipper.

Bike ran perfectly.

Developed same issue as what's described here.  No throttle when accelerating or sometimes coming to a stop...bike dies, check engine light comes on.  It's VERY dangerous.

My OBD2 scanner says the code is P2138.  I look up on the internet. Says throttle position sensor.

I bought a brand new TPS from Yamaha and had it installed.

Rode the bike for an hour and went to my GF's house for dinner and it rode great.

I left her house and it did the same issue on the way home.  I was accelerating from about 50 to 70 mph in 5th gear.  The bike started stumble a little bit and just shut off, I got off the highway coasted to the shoulder and the check engine light came on.  Restarted no problem and road it home.  Scan the code and again same code, throttle position sensor.

What do I do at this point? Replace the acceleration position sensor on the throttle body? Or just replacing the entire throttle body which comes with new sensors?.

Again, this bike has been perfect for the last 11,000 miles...

Thoughts?

[pgeldz]

On 10/23/2023 at 1:15 PM, pgeldz said:

Well, add me to the list with the same exact problem.

2019 Tracer 900 GT.  11,000 trouble free miles.  Flashed by Ivan, and also have a Rapid Bike RACE with auto blipper.

Bike ran perfectly.

Developed same issue as what's described here.  No throttle when accelerating or sometimes coming to a stop...bike dies, check engine light comes on.  It's VERY dangerous.

My OBD2 scanner says the code is P2138.  I look up on the internet. Says throttle position sensor.

I bought a brand new TPS from Yamaha and had it installed.

Rode the bike for an hour and went to my GF's house for dinner and it rode great.

I left her house and it did the same issue on the way home.  I was accelerating from about 50 to 70 mph in 5th gear.  The bike started stumble a little bit and just shut off, I got off the highway coasted to the shoulder and the check engine light came on.  Restarted no problem and road it home.  Scan the code and again same code, throttle position sensor.

What do I do at this point? Replace the acceleration position sensor on the throttle body? Or just replacing the entire throttle body which comes with new sensors?.

Again, this bike has been perfect for the last 11,000 miles...

Thoughts?

Posted just now

  On 10/23/2023 at 7:45 AM, skipperT said:

If your bike is a 2019 then you have a different system than the newer model being discussed in this thread. 

you may want to start a new topic? That might get more answers and discussion from the community. 

regardless, you can swap the sensor that you just installed for the APS to see if your problem goes away. Or if you fancy throwing parts at a problem without further diagnosis, then installing another new sensor would make sense. 

I would ensure that they are both calibrated correctly - this is a critical step. The YCC-T system is designed to throw codes and go into limp mode if the values seen by the sensors vary even slightly in relationship to each other. 
dirty pins/connectors on the harness side will also cause this problem. 

-Skip

Expand  

Looks like the problem is solved!

So, Amazon OBD II scanners can only get you so far...

What looked like a TPS sensor gone bad actually turned out to be the APS sensor (Acceleration Position Sensor) instead, and it had to be calibrated with the Yamaha dealer tools for it to operate correctly.

 

Recap:

We originally replaced the TPS and did a throttle body sync (without the dealer tools), and bike had same issue.

Replaced the APS and then a different issue - bike would act like it would start but wouldn't actually turn over, so my guy installed the original APS (thinking I could return the new one I just bought) and said probably needs further diagnostics form the dealer because they have specialty tools.

 

He was right!

 

Took it to the dealer, they hooked it up to the Yamaha Dealer tools that drills down further than my generic OBD II scanner and it said it was the APS, with a specific note saying it wasn't signaling to something, etc. (I forget the exact note).

He took it off right in front of me, moved the guts with his finger and showed me the range of movement wasn't correct and couldn't even get to where it needed to be.

He then hooked up the "New" APS I brought with me, moved the guts with his finger and showed me had the proper range and values like it should.  He installed it, calibrated it, and bike issue is solved.

When I asked him why it didn't work the first time we installed it, he said, "There is about a 40% change it'll work as-is, but they really need to be calibrated with the special Yamaha Dealer Diag tools."

He did that, and it was fine.  So it looks like there WAS an issue with my original APS, and the new one calibrated by the dealer with their special Yamaha Diag tools fixed it.

 

 

- Paul