Good news there, UpMap has mapping specifically for that pipe. Pretty sure the map disables the butterfly valve after which you can either remove it or just ignore it (that's my current plan).
Good news/Bad news
- Thread starter RennyRacer
- Start date
Joined Sep 2017
595 Posts | 121+
Lansing Mi
Its actually called a "judder spring". The kit(and all the bikes other than the 821) come with them already. Basically either a steel plate that is bent in place of a normal steel plate in the clutch pack on most clutches but on the 821 it's a steel ring that is machined out closest to the hub to allow for a smaller version of the twisted steel plate. Flat next to the twisted judder spring.
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
Sweet! Next project coming up!
Btw, my first indication of KTM troubles was riding home from Circuit of the Americas. Quit dead. Finally started but running rough. Rode back to PA. Butterfly Servo motor fail!
Not sure about the KTM one, with Ducait it defaults to open, I closes a certain revs (speeds maybe?) and then opens again when out of that range. Ostensibly to provide back pressure for more low end torque but it's really just a sound issue.
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
I also think the trans shifts well, problems finding neutral when cold notwithstanding, I've come to love the piezo actuated quickshifters (Starlane, HealTech, etc.). They are bolt on (some bikes I had to do some splicing on but there's a plug in one for our bikes, think I have in the garage), work up and down shifting and tunable using your phone. Just need to work on that little shift lever that keeps working loose...
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
Al you Duc fans, this is the most informative site I’ve ever hooked up with! Moved to CA from Pennsylvania in August. Left all my ride bros in PA. Yeah, I’m an old fck, but still still on two wheels. Gonna try to hook up with nor-Cal crazies when I get this engine/shifter glitch sorted!
As I understand it, the term belleville refers to a plate or a washer that is designed to change shape as pressure is applied. Most of the Ducati clutches, especially the dry ones, had one steel plate that was dished or, in the case of aftermarket ones, just plain wavey, and it was intended to progressively flatten as the clutch engaged, softening the take-up. I don't know if Ducati thought that a wet clutch on the 821 motor wouldn't need it but the action became very fierce after some mileage, leading to an update and revision on later versions.
Nick
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
Joined Mar 2013
3K Posts | 161+
Naples, IT
Renny,
Greetings and sorry for the late reply. While you have a 939, there's some early gen stuff you should consider since your miles are so low (you can search the site for all these):
1. Software/ TSB's up to date? The 821's had a false neutral/ stalling issue early on, normally in the higher gears.
2. EVAP canister. They suck. **** can it unless California will send you to Alcatraz for cabon footprint abuse.
3. Fueling in stock form is not great. Pipe, high flow filter and tuner transform the motor and drivetrain interaction. A 14T front sprocket is fabulous, if you're feeling really froggy.
4. Flapper valve. Pretty sure it's mostly for noise abatement at low RPM. Makes sense to disable if you're running a pipe/ filter/ tune. Can simply remove the wire that connects to servo or disable servo under the seat (possible CEL).
5. Clutch. I say if you're gonna crack the tranny to add a judder kit, might as well just do the hydraulic swap. The 939's were plumbed a little better for this mod. $$$.
6. Lithium battery. Stupid simple way to cut 5 lbs. That and an aftermarket slip on is like 15 lbs cut.
I've got 22K miles on my 2013 and have had most of the common issues (except the disco dash...). Still love it. Pulling the fuel tank and replacing the starter aren't fun but, she's not too hard to work on. Center stand facilitates a lot of maintenance which is why I'll never remove mine.
Greetings and sorry for the late reply. While you have a 939, there's some early gen stuff you should consider since your miles are so low (you can search the site for all these):
1. Software/ TSB's up to date? The 821's had a false neutral/ stalling issue early on, normally in the higher gears.
2. EVAP canister. They suck. **** can it unless California will send you to Alcatraz for cabon footprint abuse.
3. Fueling in stock form is not great. Pipe, high flow filter and tuner transform the motor and drivetrain interaction. A 14T front sprocket is fabulous, if you're feeling really froggy.
4. Flapper valve. Pretty sure it's mostly for noise abatement at low RPM. Makes sense to disable if you're running a pipe/ filter/ tune. Can simply remove the wire that connects to servo or disable servo under the seat (possible CEL).
5. Clutch. I say if you're gonna crack the tranny to add a judder kit, might as well just do the hydraulic swap. The 939's were plumbed a little better for this mod. $$$.
6. Lithium battery. Stupid simple way to cut 5 lbs. That and an aftermarket slip on is like 15 lbs cut.
I've got 22K miles on my 2013 and have had most of the common issues (except the disco dash...). Still love it. Pulling the fuel tank and replacing the starter aren't fun but, she's not too hard to work on. Center stand facilitates a lot of maintenance which is why I'll never remove mine.
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
Again, members here rock! Thanks for some more worthwhile info. At least there’s a logical progression of fixes that lay ahead. My main disappointment is that one of my best buds 821 was glitch free. Just change the oil and filter, he said!
Joined Mar 2013
3K Posts | 161+
Naples, IT
Ya, a glitch free Hyper is more rare than a unicorn fart. The important stuff holds up pretty well: DTC, ABS, Motor. And, most people only join forums to find fixes to problems. If you develop brake noise, be sure to search that. Was an early problem that most of the time wasn't a problem.
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
Please God, not that ! Happened on my KTM just out of warranty! Wrote a stern letter to KTM US. They agreed to cover it. Galfer rotors and new pads!
Joined Mar 2013
3K Posts | 161+
Naples, IT
I still argue that it's normally just the bobbins that allow the rotor to float getting dry and locking the unit in place. Little gun lube and the spin free. There are better pad choices but pretty cheap upgrade.
It's named after Julian F. Belleville who cam up with the idea of turning a washer into a spring. It's deliberately wavy or dished and when squeezed sufficiently it become flat which also keep pressure on bolt or nut offer a form of locking (resistance really) feature. Judder spring in the clutch looks like the same thing. All Belleville washers are essentially springs. Please forgive me if this feels in any way pejorative, that is not my intention...
Joined Oct 2020
76 Posts | 11+
Santa Rosa CA
Good stuff! Not only will I get this Duc up to spec, I’ll know why!
If the problem of brake 'noise' is actually judder (that word again!), then it's been around forever, especially on Brembo-equipped Ducatis. Generally, if you free the bobbins, the problem disappears. Spinning the bobbins while flushing with contact cleaner usually does the job, but some need more than that. On our ST3, I levered gently at the bobbin springs to reduce the clamping tension and improve the floating capability, and it worked a treat.
Joined Mar 2013
3K Posts | 161+
Naples, IT
Even the upgraded Brembo calipers my dealer goodwilled me make noise when the bobbins freeze. I have a gun lube with a very fine needle tip that I coat the race with and then rotate the bobbin until it spins smoothly.
Northern California you say? I'm in SF, there's a bunch of Ducati owners in the area who hold meet-ups and rides (well not so much with the current state of things, but still). Good group and also a good way to find all the fun backroads.
