V-Twin
Is your Indian motorcycle stalling unexpectedly?

Maybe the throttle is misbehaving?

Perhaps your motorcycle feels like it has less power or extra twitchy?

Does your engine hesitate to rev-up when you twist the throttle?

They may all be related, and the solution is simple, but the explanation is little more complicated.

Even if your Indian is performing perfectly, it may be worth the read.

Let's dive in.  Most modern motorcycle throttle body employs an Idle Air Control (IAC) Valve. The IAC is a small bypass passage that lets air through the throttle body with the butterfly closed completely. An electronic valve controls the air flow through that passage. This is how the idle is maintained on many motorcycles today. You might be thinking, why don't we crack open the butterfly a tiny bit like in the carburettor days? It's because the electronic motor that controls the butterfly couldn't adjust in small enough increments - the effect would be wildly fluctuating idle. Having a smaller passage, the IAC could control the idle with greater precision (more stable idle).

idle-air-control.jpg 

By the time Polaris was designing the Thunder Stroke 111 engine in 2011-2012, the electronic motor on the throttle body was capable of making tiny adjustments. That is why, on our engines, we don't have IAC. The Engine Control Module (ECU) cracks open the throttle butterfly a tiny bit to maintain the idle.

You might be able to appreciate the importance of precise calibration of the throttle. If the ECU thinks the butterfly is 3% open, but it is 1% open, the engine stalls.

If the grip is twisted to achieve 30% throttle, but the signal sent to the ride-by-wire throttle body is only 20%, the rider will notice the sluggish performance.

The opposite is true.  If the rider is maintaining a low rpm slow manoeuvre and wanting 10% throttle, but the throttle body opens to 15%, the rider will think the bike is twitchy.

The relationship between the throttle grip and the throttle body may not be linear either.  The Indian tune that accompanies the performance modifications do make the throttle mapping more aggressive with every stage.  For example, the throttle mapping for the 'Stage 1 Pipes and Air Cleaner' seem to be more aggressive than the OEM mapping.  The Stage 2 Cams throttle mapping seems to be more aggressive than the Stage 1 mapping.  And so on.  So the little twist on the grip will get you more revs with Stage 3 Big Bore kit.  So the precise calibration of throttle becomes more important with aggressive throttle mapping in my humble opinion.  

What's the fix?

The Throttle Relearn Procedure will recalibrate the throttle so that you get what you were expecting.

After the throttle has been recalibrated, some riders couldn't believe it was the same bike! The difference can be 'night-and-day' (if your bike needed the calibration) or you feel no change (if your bike was correctly calibrated). In any case, I would ask your workshop to perform the Throttle Relearn Procedure at every scheduled service.
Let's be kind to one another.
Melbourne, Victoria
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rusty
Well explained V-Twin . Do you know if same for Scout .

Russell
No one makes it out alive .
Brisbane Qld
Red Bobber only two in Brisbane hope it stays that way .ha

 

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V-Twin
rusty wrote:
Well explained V-Twin . Do you know if same for Scout .
I don’t know about Scouts/Bobbers...

  1. Does Scouts come with ride-by-wire throttle? Yes.
  2. Does Scout throttle bodies have IAC? No idea.
  3. Is the Scout ECU as sophisticated as Thunder Stroke ECU and allows throttle calibration? Also no idea.

Sorry Rusty.  Maybe someone else can chip in and offer you the answer.
Let's be kind to one another.
Melbourne, Victoria
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AAMC
It's certainly fixed the idle stability on a few other bikes we carried out the procedure on and those owners couldn't be happier with the improvement. 
It certainly doesn't need to be done at every service. ONLY if the bike develops an issue with unstable idle / stalling. 
We haven't seen the same issue with Scout (apart from the reflash that fixed the idle instability) but I'll check if it has a relearn procedure too. 
Kind regards
Rick
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MalR

Is this something that can be done by us as owners or is it an Indian Specific thing that needs to be done

 

I was chatting to a guy I met a couple of weeks ago who I believe is on this page, has a Roadmaster and mentioned the same procedure.  

 

My Chief since the day I purchased it new has always had a very annoying and sometimes dangerous flat spot straight off idle, can catch you out if you have slowed into a corner and go to throttle out, there is nothing for a few seconds and then all of a sudden more power than you want or need.  Also has had many times stalled when slowing down at lights etc, hoping this may be the cure

Will be doing cams and exhaust in coming months as well as Cat removal however would like to get this sorted first to be honest.

Melbourne - Victoria
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Dr.Shifty
I was talking with Rick at AAMC in Ringwood about two weeks ago and he was going to chase up the procedure and send me the details. It sounds like something that an owner can do by the way he was talking. However, he's not sent it yet.

Perhaps you can chase it up with Rick directly. At least give him a call and ask about it.
Cheers, Kim.

From Woodrising (no, nobody else has heard of it either)
Rides a Springfield Dark Horse
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Dr.Shifty
My previous post was 8 months ago and Rick seemed to have forgotten to send me the details of the procedure.
Cheers, Kim.

From Woodrising (no, nobody else has heard of it either)
Rides a Springfield Dark Horse
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Numbat
Has anyone actually done this procedure or had it done by their dealer or techie?
Brad - SoR, Perth WA

2018 Indian Chief Vintage (Willow Green & Ivory)
Stage 3 116 Big Bore Kit, Stage 1 Pipes, fishtails & air cleaner
Beach Bars
IMRG: AU102531
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Numbat
Hey V

I contacted Mandurah Holden today and spoke with the service manager. After speaking with the Indian techie she advised that the throttle learn procedure is only applicable to the Challenger.? Not suitable for the vintage apparently. 

Will book in the next couple of weeks to get the Fob resynced and get them to look at the stalling issue


Brad - SoR, Perth WA

2018 Indian Chief Vintage (Willow Green & Ivory)
Stage 3 116 Big Bore Kit, Stage 1 Pipes, fishtails & air cleaner
Beach Bars
IMRG: AU102531
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V-Twin
Numbat wrote:
I contacted Mandurah Holden today and spoke with the service manager. After speaking with the Indian techie she advised that the throttle learn procedure is only applicable to the Challenger.? Not suitable for the vintage apparently. 
The Throttle Relearn Procedure has been carried out on my 2016 Indian Chief Vintage.  It made a noticeable difference.
Let's be kind to one another.
Melbourne, Victoria
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Numbat
If you don’t mind me asking which dealer did it V .  I might refer our local to them for advice. Cheers 
Brad - SoR, Perth WA

2018 Indian Chief Vintage (Willow Green & Ivory)
Stage 3 116 Big Bore Kit, Stage 1 Pipes, fishtails & air cleaner
Beach Bars
IMRG: AU102531
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V-Twin
Numbat wrote:
If you don’t mind me asking which dealer did it V .  I might refer our local to them for advice. Cheers 
No problem.  All American Motorcycles.
Let's be kind to one another.
Melbourne, Victoria
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