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Discussion Starter · #1 ·
I have noticed the really disgusting/ irritating, low RPM steady hunting lean surge / stumble on a couple bikes demo bikes I've considered...dealer claims nothing is wrong ..that's BS
had similar problems on other bikes like BMW I own in past (thanks to our too lean emission standards)...what is the preferred fix for this mess on the Multi's ?

In doing searches , have seen all kinds of fixes /names/products thrown around...anyone tried a product out of Denmark called Booster Plug ? Seem like a good easy fix to me
Forgot to copy their address, but I think it's BoosterPlug.com ... they have plug 'n play units for all kind of bikes

thanks in advance
 

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Seeing as you stated this experience on multiple bikes, different brands, maybe it's you riding style?
 
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Discussion Starter · #3 ·
My riding style is to try to be smooth, and after 50+ years of riding I can certainly sense a lean condition at low rpm that is causing a chugging / hunting/and fuel not metering correctly or sufficiently
and I can definitely feel a stumble / hesitation upon adding throttle ....I'm not lugging or flogging it....it's not just me, there is a lot of dialog about this issue elsewhere /or bikes...if you don't have this problem , I'm happy for you
Most of my bikes have been carb equipped , but the BMW I was referring to is a 96 R1100 gs it was really bad,I was lucky to find a german Mechanic that could fix it, he plugged in a euro module/program that richened ,
it's been fine for 20+years . I have a 98 900SS/FE...same year Ducati started "fuel infection" on the new 99 SS's those really sucked ...naturally I bought the final edition last of the carbs ...still have it/love it/done everything to it,
but guess I will let it go to a new home, as my old body is not happy on sport bikes any more ...so here I am with a new Multistrada "project" / problem <sigh>
 

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if you disable the closed loop function via an ecu reflash that's a better solution than an add on that plugs in to manipulate sensor outputs like the booster plug or the lambda sensor "optimisers" or fatduc, etc.

anything closed loop will potentially run a you describe, and you can't "tune" them in the low throttle area as is due to the closed loop.

the 99 ssie was open loop, and if they ran bad it was just poor set up.
 

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Discussion Starter · #5 ·
Thanks Brad for that info, I will have the dealer reload/tweek the ECU ...unless there is some damn "legal" issue with the dealer making it "richer"
if so , I heard the rumor there are a few computer geeks in the Seattle area<grin>
I'm just an old analog guy
 

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I have noticed the really disgusting/ irritating, low RPM steady hunting lean surge / stumble on a couple bikes demo bikes I've considered...dealer claims nothing is wrong ..that's BS
By low RPM, are you saying "low speed"? Many of the latest bikes now come with what we would call a "no stall" function in that the ECU does not let allow the RPM to drop so low that you might stall the engine.

When you do allow the RPM to drop, while in gear, the ECU bumps it back up and you get the surging.

Some people have a big problem with it but others (like myself) have just never developed the habit of letting the RPM drop real low (without pulling the clutch) so we never see it.

But if the surging is a higher RPM (say 2K+) then that is a different issue.

Hope This Helps.

M./
 

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I have the same issue on my bike. Surges back and forth around 4500rpm. Your best bet is to get the Tuneboy software and re-flash the ecu yourself. The dealer isn't going to be much help
 

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I have the same issue on my bike. Surges back and forth around 4500rpm. Your best bet is to get the Tuneboy software and re-flash the ecu yourself. The dealer isn't going to be much help
Yes, in many cases with the very latest bikes there is nothing a dealer can do as the issues are in the tune and the tune has to maintain it's EPA/EuroX certification.

I have a new Indian and it has a very high end Bosch ECU.

There has been a ton of work done by the owners and DynoJet to eliminate issues with the tuning.

And even though at first it seemed insurmountable, riders are able to get their bikes to run near perfectly. Now that the groundwork has been performed by the early adopters it is pretty easy for the rest of us. The problem areas have been uncovered and easy to tune over.

But a dealer is hamstrung in that they cannot legally alter the tune in a way that would allow excess fuel (excess as in more than the EPA/EuroX certified factory tune allows).

HTH.

M./
 

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Thanks Brad for that info, I will have the dealer reload/tweek the ECU ...unless there is some damn "legal" issue with the dealer making it "richer"
if so , I heard the rumor there are a few computer geeks in the Seattle area<grin>
I'm just an old analog guy
the dealer cannot tune it. that's the point, it's closed loop. it's not because they're idiots, as a lot of people like to make out. if they (the workshop staff) say they can it's because everyone up the management food chain from them expect them to lie to protect the brand. i spent 14 years as a dealership tech, head tech and service manager. been there, done that. they just aren't allowed to say "they all do that, that's how it is from now on" because everyone up the chain gets pissy when they get fronted by owners who have been told the truth.

there is no capacity in the ecu to externally adjust the mixture as the ecu does that based on the lambda sensor feedback. it has to be closed loop for it to pass emissions standards as that's the only way the cats will work to pass the testing.

dealers may have the ability to reflash it via third party tools, but then they are breaking the law as such, as is any other business that reflashes ecu to disable closed loop. and most likely breaking their franchise agreement.

it's just how it is. all closed loop bikes will surge to some extent. some are quite good, some (of the same model) can be terrible. i think it's the relationship between crank inertia and total vehicle inertia - bikes don't have the overall vehicle mass to mask the crank speed variation closed loop seems to set up.

it varies with owners too. i rode an r1100s once that the owner claimed didn't surge, and i thought it was one of the worst i had ridden.

if you simply flash it to be open loop and clear the adaptions (do nothing else actual fuel mapping/tune wise) it will be a much different bike.
 

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Closed loop operation is basically a "constantly hunt stoich" situation... some number of times per second the a/f ratio oscillates between rich and lean. You'd have to get an engine controls expert in here to give you an authoritative reason WHY they do it that way... but I'm guessing that a combination of the input/response lag (the delay between when a control adjustment is made and the response happens) and the unpredictable nature of engine load makes it impossible to tightly control A/F ratio.

Maybe I've got a "good" bike... but I routinely have run in the 3k'ish range touring and have never noted surging. I have noted a lope/surge when at idle but as long as the bike doesn't stall I don't care what happens at idle.
 

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Discussion Starter · #12 ·
Hey thanks for the feedback guys, ya'll have confirmed most of my suspicions . I didn't/don't expect much help from the dealer, I know their hands are tied on some matters/issues like this,
but when asked how I liked the S after the test ride , and I started giving my feedback/complaints/disappointments , I got a "deer in the headlights" look from the sales manager .."we don't see that" he says,
then says, "maybe you are holding it in the DVT range of transition" " and that is causing the hunting and surging"...HUH ?...damn I thought the DVT was supposed to be an improvement/ better than previous generation..duh.

Where it's most noticeable is ,for example , in traffic starting off stumbling /jerking to 2-3k rpm then holding that speed rpm range , a lot of surging ,course using the clutch too...I'm in traffic but am not lugging it down to 1k, in gear
but under a load/ acceleration into 2nd, then 3-4 -5k rpm not as bad, much better ...but having said that, I haven't had good weather conditions to get frisky....and since it's brand new, not flog it over 5 k.

I remember back in 96 when I bought my R1100 GS new, this same lean stumble/surge was driving me nuts , and of course I was bugging the dealer , well I was at some BMW dealer function/party at that time,
saw the area BMW rep there and pulled him aside...( he was an ex helicopter pilot like myself) I said something like " Listen..if this damn thing was an aircraft...you wouldn't fly it!!!!" I remember he looked down,
nodding his head ..off the record he agreed with me, but on the record ,he reminded me he had to toe/walk the BMW company/corporate line <sigh>
 

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Hey thanks for the feedback guys, ...
nodding his head ..off the record he agreed with me, but on the record ,he reminded me he had to toe/walk the BMW company/corporate line <sigh>
The Multi engine is not happy at 2k... and BARELY happy at 3k. I can cruise at 3k without a problem but if any substantial throttle input is required then a shift down is needed. The DVT is better but still not really happy. That's definitely a design choice from Ducati. If you're a "low rev's" rider then you're going to be happier with the GS. Incidentally... I get better mileage on my DVT Multi touring (>50mpg, even though the rev's are a bit higher) than I did on the 17 GS that I rented for touring in Germany (44 mpg over 1500mi) - so it's not like the Multi isn't efficient - just the designed rpm range performance.

The motor response is one of the bigger differences I found between the GS and Multi. The GS would happily putt along at low 2k rpm... but when you were on go, just when the Multi was starting to really rip the GS would be wheezing and needing a shift. Both are awesome bikes and great motors... but they're a lot different.

Here's the low rev test I did with my bike a couple years ago... it tested out the 2-3k range during a ride. You can see from the video that there wasn't surging at those motor speeds but there was a lot of vibration, especially under even light throttle (easily seen in camera shake). IMO it shows that you CAN ride under 3k... but the lower you go below 3k the quicker the bike gets unhappy under throttle.

https://vimeo.com/140375770
 

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Closed loop operation is basically a "constantly hunt stoich" situation... some number of times per second the a/f ratio oscillates between rich and lean. You'd have to get an engine controls expert in here to give you an authoritative reason WHY they do it that way... but I'm guessing that a combination of the input/response lag (the delay between when a control adjustment is made and the response happens) and the unpredictable nature of engine load makes it impossible to tightly control A/F ratio.
i believe the cats like a mixture that cycles around stoich, but the main reason it is done that way is due to the nature of the sensors. they're a narrow band sensor, which is a galvanic cell that outputs a voltage when there is not an excess of oxygen in its environment. as such its output is either greater than 0.8v or less than 0.2v, which as an ecu input is a yes/no - it can sense rich and lean, but not degrees of to any accuracy.

the ecu has to react to what signal it gets to make the signal change, then once it has changed, go back the other way to make it change again. so if the voltage is high, it's rich so it makes it leaner until the voltage is low, then it makes it richer until the voltage is high, then leaner and so on. only at constant throttle and rpm. it can't work in any transitional situation.

the ecu also has an adaption table, which is a historic record of what it has done in the past to hit the switch point and cuts down the time it takes to hit that point in use.

a wide band sensor is needed to read afr
 

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The REXXER tune eliminated my low RPM hunting/surging and smoothed out acceleration from idle all the way to the redline!

The Multi engine is not happy at 2k... and BARELY happy at 3k. I can cruise at 3k without a problem but if any substantial throttle input is required then a shift down is needed. The DVT is better but still not really happy. That's definitely a design choice from Ducati. If you're a "low rev's" rider then you're going to be happier with the GS. Incidentally... I get better mileage on my DVT Multi touring (>50mpg, even though the rev's are a bit higher) than I did on the 17 GS that I rented for touring in Germany (44 mpg over 1500mi) - so it's not like the Multi isn't efficient - just the designed rpm range performance.

The motor response is one of the bigger differences I found between the GS and Multi. The GS would happily putt along at low 2k rpm... but when you were on go, just when the Multi was starting to really rip the GS would be wheezing and needing a shift. Both are awesome bikes and great motors... but they're a lot different.

Here's the low rev test I did with my bike a couple years ago... it tested out the 2-3k range during a ride. You can see from the video that there wasn't surging at those motor speeds but there was a lot of vibration, especially under even light throttle (easily seen in camera shake). IMO it shows that you CAN ride under 3k... but the lower you go below 3k the quicker the bike gets unhappy under throttle.

https://vimeo.com/140375770
 

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Discussion Starter · #16 ·
Thanks guys, First time I spent a little time on it this week, I began to get a little buyers remorse, and wonder if I had made a big financial mistake , with all this new digital"flybywire'geewizz techknowledgy
What you're saying Brad makes sense even to my old analog brain ...thanks, now I have more hope...and Dave I don't disagree with anything you said(thanks for the Video, makes me wanna ride 'cept its raining)
but my problem is not shake / vibration/ even shudder ,( heard about that before I bought this Multi) but the chugging/surging/stumble at steady low rpm (while working clutch ) in traffic at say a jogging speed.
( at least the clutch is not brutal like my two old beveldrive's ) and I'm not wanting to motor around at low rpms (never have had a Harley or cruiser type bike) but when you are in 1st gear , ya can't go any lower
I live in the country so don't have to deal with too much traffic , but when I do, I don't want a bike that is gonna to jump or lurch on me ...it's a safety issue also, not just an irritation.
 

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Closed loop operation is basically a "constantly hunt stoich" situation... some number of times per second the a/f ratio oscillates between rich and lean. You'd have to get an engine controls expert in here to give you an authoritative reason WHY they do it that way... but I'm guessing that a combination of the input/response lag (the delay between when a control adjustment is made and the response happens) and the unpredictable nature of engine load makes it impossible to tightly control A/F ratio.
Narrow band O2 sensors are only capable of identifying one mixture ratio accurately. Wide band sensor do not have that problem. Stoichiometric is a mixture ratio that identifies maximum efficiency of combustion. Since it is too lean for "under load" conditions in an internal combustion engine, it can only operate when idling or running at constant low power settings.

The most important final component for emission reduction is the catalytic converter. Hence, part of the programming employed for O2 sensor based mixture control is to protect the converter as much of the time as possible. Rich mixtures consume the base materials of the converter through execs heat. Without catalytic converters we would be swimming in a murk of pollution. Many new vehicles actually emit less pollutants of some key elements that they are intaking.
 

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i believe the cats like a mixture that cycles around stoich
It's because a modern catalytic converter is doing two different things. In the rich part of the cycle, it's removing NOx from the exhaust. Then in the lean part of the cycle, the cat burns the hydrocarbons in the exhaust...


To operate efficiently, three-way converters need an air/fuel mixture that alternates between rich and lean. When the air/fuel mixture is rich, it reduces the amount of oxygen in the exhaust. This allows the reduction catalyst to break down NOX. But to burn HC and CO, the oxidation catalyst needs more oxygen so the air/fuel mixture has to go lean. This allows the catalyst to momentarily absorb oxygen and trigger a reaction that burns up the HC and CO.

The powertrain control module (PCM) flip-flops the air/fuel mixture when the engine is warm by monitoring the rich/lean signal from the oxygen sensor in the exhaust. When the O2 sensor reads lean, the PCM makes the fuel mixture go rich. When the O2 sensor sends back a rich signal, the PCM shortens the on-time of the fuel injectors and leans the fuel mixture. The O2 sensor then send back a lean signal, and the PCM increases the on-time of the injectors to make the fuel mixture rich again. By rapidly changing the air/fuel mixture back and forth, the overall mixture averages out and keeps emissions at a minimum.
 

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Thanks guys, First time I spent a little time on it this week, I began to get a little buyers remorse, and wonder if I had made a big financial mistake , with all this new digital"flybywire'geewizz techknowledgy
What you're saying Brad makes sense even to my old analog brain ...thanks, now I have more hope...and Dave I don't disagree with anything you said(thanks for the Video, makes me wanna ride 'cept its raining)
but my problem is not shake / vibration/ even shudder ,( heard about that before I bought this Multi) but the chugging/surging/stumble at steady low rpm (while working clutch ) in traffic at say a jogging speed.
( at least the clutch is not brutal like my two old beveldrive's ) and I'm not wanting to motor around at low rpms (never have had a Harley or cruiser type bike) but when you are in 1st gear , ya can't go any lower
I live in the country so don't have to deal with too much traffic , but when I do, I don't want a bike that is gonna to jump or lurch on me ...it's a safety issue also, not just an irritation.
Well, the first thing you need to do is either go down one tooth on the front sprocket or up 2-3 on the rear. The bike is geared way too tall as delivered, and I've heard it strongly hinted that's because of the parameters of how the noise testing or smog testing is done.

I hardly ever ride at what I'd think of as a jogging pace, but gearing down would most certainly help. And to use a technical term, it's a shit-ton more fun at an elevated pace.
 

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Well, the first thing you need to do is either go down one tooth on the front sprocket or up 2-3 on the rear. The bike is geared way too tall as delivered, and I've heard it strongly hinted that's because of the parameters of how the noise testing or smog testing is done.

I hardly ever ride at what I'd think of as a jogging pace, but gearing down would most certainly help. And to use a technical term, it's a shit-ton more fun at an elevated pace.
This is a good idea too... I went +2 last year and was very happy with how it livened up the bike, this year I just went -1/+2 and the one ride I got in I again felt quite a difference in throttle response. In sport mode I needed to be pretty gentle on the throttle... was pretty 'direct'.
 
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