How I eliminated the twitchy throttle

[Pursuvant]

Just keep going, more of a good thing. If the cable adjuster can support this? not sure but will check

On the stock throttle tube (softer black plastic) I thought I cut too close, but was surprised how the "island" held up (only cut one side for the cable). This R6 tube is much more stout, this image above would be way strong. And cable ends pull opposite, they won't interfere with each other and only "touch" if rider has excessive cable slack.

For sport - ultra short range of minimal diameter at idle +4% to fix the "twitchy" then jump to quicktwist - good for the lowest WOT degrees of rotation number. That's what I have in mind for my R6 tube work in progress.

Commuter, do like I did on my stock prototype tube, just keep cutting around the groove far enough to create the experience of a seamless smoothing folding into the rapidly rising torque curve. Smoothing melts into rising torque - that was the experience from my stock prototype throttle tube.

 

[FZ not MT]

You guys either have too much time on your hands, or just have bad luck.

I have 10,000 miles on my 2WDW flash and my unmodified OEM R6 tube. I have a stock exhaust with a K&N filter and the snorkel removed. My power delivery is stone smooth - no twitchiness whatsoever. I was definitely able to perceive a power/torque boost with the flash.  Actually, everything about the power on my bike  is awesome. I always am amazed how good it runs after every ride. 10,000 miles later, that is a heck of a statement!

BTW, the bike had around 5,000 miles when I got the flash, and it has nearly 16,000 now.

I really think my story is the norm.

[D.A.]

14 hours ago, FZ not MT said:

...I have 10,000 miles on my 2WDW flash and my unmodified OEM R6 tube. I have a stock exhaust with a K&N filter and the snorkel removed. My power delivery is stone smooth - no twitchiness whatsoever...

How twitchy was your bike before you had it flashed?

[klx678]

I think that is the key here.  The rider that wants to soften the throttle response in initial portion of the twist without having to spend $200+ on a reflash.   I can understand it.   I seem to initially have some problem with the throttle starting out for the day, but am able to adapt shortly.   I actually like the heavy engine braking and don't have much issue with acceleration in a corner being a bit lighter on the throttle than some.   But that's just me, not everyone is the same.  It's no reflection on skills, just differences.

[FZ not MT]

On 12/20/2020 at 1:34 PM, D.A. said:

How twitchy was your bike before you had it flashed?

The word "spastic" comes to mind. There were many accidental 2nd gear wheelies as well. As much as I didn't like that powerband, it was sorta fun because it reminded me of a 2-stroke. All of that is gone, and it just pulls hard and smooth! It also knocked down the compression braking by a good 50%. I'm a big fan of 2WDW, although they may have tweaked their tuning in the last 3-4 years. Mine is great!

My bike is a 2016 which I bought in 2015, and this summer I test rode a new 2020 XSR700. Yamaha cleaned up the throttle/mapping a lot on that bike. It was pretty smooth, but it was also boring compared to mine.

 

Edited April 11, 2021 by FZ not MT

[D.A.]

3 hours ago, FZ not MT said:

The word "spastic" comes to mind...

Oh, okay. That’s reassuring. I initially thought you were saying your bike was never twitchy to begin with.

Interesting that your FZ made a pronounced transformation, going from spastic to stone smooth as a result of the flash, whereas mine went from twitchy to, well, still twitchy in spite of the flash. 

Sounds like the only hardware differences between our setups (and the only factors keeping this from being a true apples to apples comparison) is that you removed the snorkel and added a K&N filter while I did neither.

Others have suggested variations in altitude and humidity between different locales also play a role. Plus there could be just enough variation between bikes of the same model and generation that 2WDW’s one-flash-fits-all approach is, in reality, a one-flash-fits-most solution and that each individual motorcycle would see the greatest results from an in-person tuning based on that particular bike’s Dyno results. 

Part of it could be due to perception too: it’s possible you could ride my twitchy bike and think it’s smooth as butter. Likewise, I might ride your stone smooth bike and think it twitchy as all get out.

It’s been pretty clear to me from the get go my reaction to 2WDW’s cookie-cutter is not typical. On the other hand, it’s not unique either.

For all intents and purposes, I have tried your solution and was not impressed with the results. Would be interesting to have you try mine and then hear your opinion. 

Edited December 21, 2020 by D.A.

[FZ not MT]

9 hours ago, D.A. said:

Sounds like the only hardware differences between our setups (and the only factors keeping this from being a true apples to apples comparison) is that you removed the snorkel and added a K&N filter while I did neither.

That's actually a big difference. I  don't know if you ever took the lid off your air filter box, but that snorkel is pretty big, and will really mess with the air flow. I'm pretty sure 2WDW has separate options for snorkel in or out. If I had to do it again, I would have got either a DNA or MWR air filter BTW. The good news is that it only cost you $20 in round trip shipping plus an air filter to reflash your ECU.

 

9 hours ago, D.A. said:

Part of it could be due to perception too: it’s possible you could ride my twitchy bike and think it’s smooth as butter. Likewise, I might ride your stone smooth bike and think it twitchy as all get out.

Nope, it really is crazy smooth. I noticed the difference within 1/2 block from my house. I also have ridden other FZ07's without a flash, and they are the same crap with the exception of the 2020 XSR700. I was really surprised how smooth that was. It just didn't seem to have any balls. How much that had to do with my R6 tube, I don't know.

9 hours ago, D.A. said:

Others have suggested variations in altitude and humidity between different locales also play a role. Plus there could be just enough variation between bikes of the same model and generation that 2WDW’s one-flash-fits-all approach

I live on the East Coast, and have ridden on the same type of terrain and humidity that you have assuming you live in NC as your profile says, so I doubt that is a factor. Depending on what year you have, it might have something to do with Yamaha's mapping. Even though it's the same motor, they must have been doing some mapping changes based on that new XSR700 I rode.

FWIW, you could try a $100 experiment and get a DNA or MWR air filter, and send the ECU back to 2WDW, and ask for a redo with no snorkel. Perfect timing to do that as we are just starting winter. Just wait until after the New Years as shipping is hell right now. BTW, if you have any question for them, make sure you talk with Nels directly. He knows the most there by a mile.

Good luck

 

[Pursuvant]

4 hours ago, FZ not MT said:

Nope, it really is crazy smooth

Glad you joined us on the forum FZ not MT. Your experience is also mine. I had 2wdw flash my ecu with the Yosh race pipe flash, and I stuck it in a stock engine bike before I installed Pop's pipe, rode for several days with stock pipe & Yosh flash. Even my speed shop mechanic noticed the diff, smoother, more responsive, told owner we are really getting things sorted out.

But, the fundamental jerk that fuel injected bikes have on initial throttle open to low positions was still fully present. In a parking lot with clutch egaged, opening & closing throttle the bike jumps, experienced on the street when making slow side street turns, open throttle from closed to low open in the turn and you get the twitch. A carb bike can do the same, smoothly. Getting the Yosh pipe on later, changed almost nothing other than fun factor.

For this FI issue, only option I see is to reduce the rate of throttle cable pull on low open positions - that's what I targeted using D.A. 's mod on a stock throttle tube as my first test and it works.

Edited December 21, 2020 by Pursuvant
Speeeallinng horibla

[FZ not MT]

47 minutes ago, Pursuvant said:

But, the fundamental jerk that fuel injected bikes have on initial throttle open to low positions was still fully present. In a parking lot with clutch egaged, opening & closing throttle the bike jumps, experienced on the street when making slow side street turns, open throttle from closed to low open in the turn and you get the twitch. A carb bike can do the same, smoothly. Getting the Yosh pipe on later, changed almost nothing other than fun factor.

That's weird as I don't have any of that especially that "fundamental jerk". Maybe I'm just lucky. I definitely do have their first FZ-07 flash as it was done in early 2017 well before the MT was around. My unmodified R6 throttle tube has zero slack, and the bike pulls clean off idle with no jerking or twitching. 2WDW has my idle set at 1100 rpm which is OK with me.

[michigan400]

I know this won't go over well but,,,,sounds like a simple case of whisky throttle to me. 

 

[Dennis.Halmstad]

Or maybe it's just the very delicate riders with precision feel and accuracy that notices it.

It's most appearing in slow speed situations like parking lots or dense traffic, also slow speed turns and roundabouts. Might be a thing in high speed situations like mid corner on the very limit trying to ease on the throttle. 

Maybe most people use excessive amount of clutch in low speed situations and don't feel it? 

[FZ not MT]

11 hours ago, Dennis.Halmstad said:

Or maybe it's just the very delicate riders with precision feel and accuracy that notices it.

It's most appearing in slow speed situations like parking lots or dense traffic, also slow speed turns and roundabouts. Might be a thing in high speed situations like mid corner on the very limit trying to ease on the throttle. 

Maybe most people use excessive amount of clutch in low speed situations and don't feel it? 

Or maybe you got a great tune, and it just doesn't exist. I'm as anal as they come on detecting nuances with my bikes, so...

The more I read this thread, the more grateful I am regarding my bike.

[JBrock]

nice work on the throttle tube modification.

I originally did a 2wdw tune with a stock exhaust and found the throttle twitchy at low speeds. Once I did an aftermarket exhaust and had the ecu retuned, it became much more smooth. Not sure how to explain that, but was my experience.

[Low68]

This is a fantastic thread! Been lerking  here since I bought my bike(my first one) a few months ago. I did the tune with exhaust and filter and it improved it but I notice the throttle in the corners is a bit too sensitive for my taste. I bought the motion pro tube to get a little bit of reduced rotation but thought the oem r6 tube would be too much for me. Now I want to do my own throttle tube like you guys have done! Please keep the info coming!

[Pursuvant]

11 hours ago, Low68 said:

Now I want to do my own throttle tube (R6)

Just ride the R6 tube for awhile, you may like it. Before you modify the R6 tube, practice by modifying your stock tube. Then do D.A.'s mod for the R6 tube, you get better results

[seven]

Since this thread has a bunch of tuning talk as well as throttle tube changes I thought I would add in my 2 cents...

I just flashed to the 2WDW tune for an MT-07 with stock exhaust and snorkel removed and if I didn't know that I flashed the bike I honestly wouldn't be able to tell the difference, except for the fact that the temps are lower when doing slow speed maneuvers as the fans kick in earlier and off later. Engine braking is still noticeably there and the off/on throttle jerkiness is still there. Sure it might be a little less and maybe if I did a back to back comparison I could maybe tell but from one day to the next, it is very subtle.

I suspect that this comes down to me having HUGE expectations from what most people on here say about the tune, and me not having such a refined "palette" that I can easily sense a difference.

I actually just went back out to my bike to reflash it thinking, maybe I did something and the tune wasn't really written to the ECU. But when I go to write the ECU it pretty quickly comes back with a message that there are no changes to apply.

[Jerzee]

My  experience of 'What change' is similar to yours. Maybe a 'bit' less jerky at low speed, 1st gear, but I compare it to a FZ6R, which I also ride, and it's clearly a very different ride. Still smile each time I ride the 07, but the flash was not the 'fix' I expected. I guess I'm just an old guy who doesn't notice the differences.

[mt7fan]

What is the experience after just modifying the throttle tube, without flash? 

[D.A.]

9 hours ago, mt7fan said:

What is the experience after just modifying the throttle tube, without flash? 

The diameter of the cam wheel on the OEM FZ/MT-07 throttle tube is relatively small. Because of this, you must twist the throttle grip 90° to get from fully closed to wide open. That’s a big rotation that a lot of people find uncomfortable and/or annoying. 

••• Unmodified FZ/MT-07 tube •••


The cam wheel on the R6 throttle tube is larger and can therefore pull the cable faster, requiring that you only twist the grip 60° to go from closed to wide open, making it feel like the motor is more responsive and that the bike is accelerating faster. The downside, though, is using the R6 tube accentuates the FZ/MT’s inherent twitchiness. 

••• Unmodified R6 tube •••

By filing down the initial portion of the R6 cam profile, you can make the motor feel less responsive at small throttle openings and thereby mellow out the twitchiness. And by leaving the rest of the R6 cam untouched, you can maintain the sensation of quick acceleration once you get past the twitchy zone.

My current iteration R6 cam mod requires about a 75° twist to get from closed throttle to wide open. Because of the new hole I drilled, the initial portion of the cam has a smaller radius than the stock FZ/MT-07 tube, making the throttle response slightly smoother at small openings, but the immediate transition to a large cam radius means power comes on quick and strong once you get past the initial twist. In my opinion it’s the best of both worlds. 

••• Modified R6 tube •••

Of course, swapping out and/or modifying throttle tubes has no effect on fuel being cut on deceleration, air/fuel ratios, fan temperature settings, etc. To address those kinds of issues you need to alter the settings in the ECU’s software via flashing or as an alternative, use an add-on device like a Power Commander to tweak fueling. 

As I mentioned in my initial post, before modifying my R6 tube I had my ECU flashed, believing it would eliminate the twitchiness, based on what other riders had posted. But I was underwhelmed by the results. If there was a reduction in twitchiness, it was so minute as to be imperceptible, whereas the effects of the cam modifications were much more pronounced and worthwhile.

Modifying the R6 cam eliminated 90% of my bike’s twitchiness. But keep in mind, the mod was in conjunction with the other 3 steps mentioned in my first post (i.e., manually increase idle to 1400 RPMs and remove excess slack in chain and throttle cables).

Edited April 8, 2021 by D.A.

[Pursuvant]

I'm running an R6 custom grind that does much less about the twitchiness on small throttle openings, but does it ever increase the hit you feel as soon as you get rolling.

And that's another point - you cut the grind, for what ever you want. I don't want a Graves or MotionPro, I want what I want, not somebody else's $150 choice that they make for me and toss in a box

[Joaoduarte]

I think its all about throttle control, and subjective perception/sensation, i just felt some twichtiness when you go any % throttle opening to 0% throttle opening then opening again and that was the time that i had that feeling, once i learned to not close all the throttle the twitchiness disapeared completely.

But resuming i think its all about perception wich is always a subjective feeling

[seven]

11 minutes ago, Joaoduarte said:

I think its all about throttle control, and subjective perception/sensation, i just felt some twichtiness when you go any % throttle opening to 0% throttle opening then opening again and that was the time that i had that feeling, once i learned to not close all the throttle the twitchiness disapeared completely.

But resuming i think its all about perception wich is always a subjective feeling

I think I agree with you for the most part but would say it isn't just perception as it is actually happening but agree that what I consider twitchy/snatchy might not be for someone else.

I suspect that if I just had a lot finer motor control of my throttle hand that it would not be an issue. Very much like how I can practice threshold braking and squeeze the brake progressively but rapidly to simulate panic stops, but when a cat runs out in front of me or a car looks like they are about to blow a stop sign, the right hand is way more grabby. And the throttle is that same issue where I can most of the time mitigate the twitchiness by being very deliberate but it is those odd time that I don't do it right that I cause problems for myself.

[Pursuvant]

It's always been this way with fuel injected bikes. They just can't do what carb slides can, at small opening. I don't know why we are saying it is or isn't, it's just the nature of FI.

Remember the Kaw GPZ1100? That bike jumped out of its skin (and was crappy fuel injection everywhere else too), smart guy put carbs on.

It's just the nature of FI. Ya, I could just ride and ignore it, but hell no let's tinker with it and everything else.

 

Edited April 8, 2021 by Pursuvant

[Dennis.Halmstad]

Maybe its still to expensive to make it right on production bikes?

If twitchiness was thing on MotoGP bikes they would probably crash a lot more.

I don't think the technicians tell the worlds best riders "If you never completely close the throttle...." 

[seven]

5 hours ago, Dennis.Halmstad said:

Maybe its still to expensive to make it right on production bikes?

If twitchiness was thing on MotoGP bikes they would probably crash a lot more.

I don't think the technicians tell the worlds best riders "If you never completely close the throttle...." 

I think the issue is mostly related to closing and opening the throttle while at lower RPM. So far the only time I really characterize the bike as twitchy is when I am going slow, like when turning onto a residential street and I am likely in 1st gear and I am engine braking and then crack the throttle a little too much.

The bike does have a lot of torque so just the nature of the power delivery is going to be harsher than some other bikes...it's called the master of torque after all.

I suspect that if the bike also had throttle by wire this would not be an issue as you could very precisely control the throttle butterfly valve to deliver the exact amount of air (and subsequently fuel) to get the desired combustion. With the cable throttle it all comes down to the profile of the throttle tube and the "wheel" on the other end of the throttle cable.