13 NTX - soft rev limiter?

[Spuddy]

My idea is that 150 mile round trip x 2 ain't bad at all, compared to 600 miles one way.

Spuddy

[beetle]

If you can gently roll-on still (like you could earlier), then it's unlikely to be spark. If the spark was breaking down, it would do it regardless of how you roll the throttle on.

[andrewdonald1]

If you can gently roll-on still (like you could earlier), then it's unlikely to be spark. If the spark was breaking down, it would do it regardless of how you roll the throttle on.

Well I took it out for a couple hours again today.
It must have to do with the rotational rate of acceleration of the engine.. ok I was throwing in some engineering slang there.

Meaning:  1st thru 3rd gears wide open she does it.  4th wide open, she smoothly goes all the way to 8K no missing.
So I think this takes out the fuel filter as a possibility.
Also seems to take out the possibility of coils, wires and plugs I think.. although that's a hypothesis on that one.
To me it feels like lets blame it on the ECU.. It feels like its a trip to Moto International for a warranty visit.
That's ok, I want to put some new tires on it anyways.

Anyone else have input before I go down that road?

[beetle]

Bear with me, this may sound like a irrelevant question, but how accurate is your speedo? Have you compared it to a GPS?

[andrewdonald1]

I have, it's within about 1 or 2 mph.

[beetle]

OK.  ;-T That rules out that idea then.

I'm still suspicious it's the ECU activating the rev limit due to bad/inaccurate or intermittent tacho input.

[andrewdonald1]

OK.  ;-T That rules out that idea then.

I'm still suspicious it's the ECU activating the rev limit due to bad/inaccurate or intermittent tacho input.

Hold on there for a moment.. Lets explore that..

When I was doing my 6250 mile service, my right windshield pillar (black steel frames that the windshield mounts on to) was rubbing on the dash board plastic cover/surround.
When I spaced that windshield pillar out slightly I pulled the speedo/tach assembly (ie disconnected it from the wiring harness).
I am wondering if I should first go back and check that connection, although I was pretty thorough.  

Does the above sound reasonable to try before moving down the warranty path?

[Scott of the Sahara]

a not fully connected wire would respond to vibration and possibly cut out. Check it out.

[beetle]

I am wondering if I should first go back and check that connection, although I was pretty thorough. 

Does the above sound reasonable to try before moving down the warranty path?

Yes! 

[andrewdonald1]

Thanks you guys!  I'll check it out this weekend when I am back down to my weekend residence.

Thanks again for your help, all of you!

Andrew

[andrewdonald1]

So a little follow up to this story.

Had the bike in at M.I.

Micha did a great job, they really are a GREAT dealership!

Turns out it has to do with the plastic fuel pump assembly, the plastic hoses and the o-ring(s?) that seal it.
He's going to post something up at some point on their website I believe (if it turns out to be more than an anomaly), and is going to test the mod on another Stelvio tomorrow that is going in for a 2nd dyno shortly in the future.
Anyways it appears that my original stock fuel pump assembly might not be fully sealing and caused reduced fuel pressure to be delivered to the injectors.
He modified mine, and I took it for a ride today.

Its about 100% fixed.  
It runs really strong now, in fact he said its the strongest Stelvio they've ridden.. who would have know?  
I haven't ridden another Stelvio so I didn't know any different.. I know it pulls the wheel up in 1st gear if I am on the throttle hard..that's 100% stock other than swapped out spark plug boots and plugs.

As I know more, I'll let you guys know.  

[Spuddy]

I'm quite interested in your results.  I have what appears to be a similar anomaly.  (Wait a minute - if it is similar can it still be an anomaly?)  I'll report back but I'd like to get at least 1K on the clock before I repeatedly goose the goose.

Spuddy

[Cage Free]

So a little follow up to this story.

Had the bike in at M.I.

Micha did a great job, they really are a GREAT dealership!

Turns out it has to do with the plastic fuel pump assembly, the plastic hoses and the o-ring(s?) that seal it.
He's going to post something up at some point on their website I believe (if it turns out to be more than an anomaly), and is going to test the mod on another Stelvio tomorrow that is going in for a 2nd dyno shortly in the future.
Anyways it appears that my original stock fuel pump assembly might not be fully sealing and caused reduced fuel pressure to be delivered to the injectors.
He modified mine, and I took it for a ride today.

Its about 100% fixed.  
It runs really strong now, in fact he said its the strongest Stelvio they've ridden.. who would have know?  
I haven't ridden another Stelvio so I didn't know any different.. I know it pulls the wheel up in 1st gear if I am on the throttle hard..that's 100% stock other than swapped out spark plug boots and plugs.

As I know more, I'll let you guys know.  

Good info, glad its fixed.. Don't know if you checked but my dealer offers loaners if you have to leave your bike which makes leaving it much less of a pain in the ass.