14T Front Sprocket Issues...?

kuksul08 · Jul 29, 2016

Hey all,

So, my bike had been parked for the past 2 months. During that time, I installed a 14T front sprocket in anticipation of riding again.

However, now I have run into a problem that has got me puzzled. My bike is intermittently redlining at 8000RPM. I have never even once had this issue until now. I just hit 12,000 miles today. It happens right as I hit 8000RPM, usually while hard on the gas. It cuts out very abruptly, and the red light flashes. DTC is off by the way.

I've been able to reproduce it 30-40 times. Usually it's just for a second, but most recently I was able to get it to do it constantly. As I rolled on the throttle down a hill, it got to 8000RPM, and the red light stayed on, and I kept rolling on the throttle, but it stayed the same speed.

Diagnostics:
Research has pointed me to the neutral switch, clutch switch, and kickstand switch as possible issues.
-I checked the clutch switch operation and it appears to be working fine. With kickstand up and in gear, I can't start it unless the clutch is pulled in. I pulled the switch off and it looks fine, and worked correctly (via multimeter) every time I pressed it.
-I took off the neutral switch grommet and it looked fine. Nice and tight, no corrosion. When this issue happens, the neutral light is NOT illuminated.
-The kickstand switch seems to be operating correctly as well, tested via multimeter.

Has anyone else had this problem with a new front sprocket...? It makes no sense to me, because it can happen in any gear. Does the bike know what gear it's in? Did Ducati do something stupid with the rev limit tied to the gearing? I'm stumped. Pending your responses I might put my 15T back and see what happens.

appliance821 · Jul 30, 2016

There was a thread that touched on this recently - the title had something to do with rev limit. Keep us posted- I think that those of us interested in some dirt will be doing this so info will be helpful.

zippy49 · Jul 30, 2016

Wow, that's a puzzle. However, my motto is:

"Whenever something goes wrong, look at the last thing you touched."

My guess is that the sprocket change messed up the ABS.

robbub · Jul 30, 2016

I have had a 14t on for 1500 mi and have never had this issue; the exception being when I swapped out my clutch lever and let the switch dangle.

My guess is that it is still either the neutral switch or clutch switch (probably the clutch switch). Could try taking them completely out of the equation by making a jumper across the connector pins and see what happens. The fact that it is intermittent suggests a loose or poor connection. Possibly more apparent due to increased vibration from the 14t. Who knows..but that is where I'd continue my investigation before I put the 15t back on.

Try just pulling the switch out of the clutch perch and ziptie-ing the microswitch closed so it doesn't cycle each time you shift. Go for a ride and report back.

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kuksul08 · Jul 30, 2016

Ok, little update here.

I went out to a straight stretch of road where I could get through the first 4 gears to redline, and I just went back and forth.

It only happens in 2nd gear. 1st, 3rd, and 4th have no issues and can easily get to redline. I was able to repeatedly make this happen by rolling on the throttle in 2nd. As soon as it hits 8000, the red light comes on and it just stays there. If I'm accelerating quickly WFO, it will pass this 8000-8500 zone, and then begin to accelerate again afterward, causing a very jerky ride...

So that's kinda weird. I'm going to swap out the sprocket and do the experiment again, unless someone has a better idea. I tried with DTC and ABS off. No difference.

I found someone else with the exact same problem and lo and behold, they have a 14T sprocket. http://www.ducati.ms/forums/92-hypermotard/530418-821-rev-limiter-problem-2nd-gear-only-help.html

So... some of the bikes have this, and some don't...?

kuksul08 · Jul 30, 2016

Update:

Put the 15T sprocket back on. No more issue. I rode for over an hour and it didn't happen once.

WTF!!! I can't change the gearing on mah bike? How dumb is that.

toeslider · Jul 31, 2016

Welcome to the future Patrick. Bikes are becoming increasingly more tamper-proof thanks to all those well-meaning folk in the European parliament. The New Euro 4 regs even require diag plugs so that the police can make sure the ECU hasn't been 'hacked' when they pull you over. Our brave new Euro 4 world starts on January 1.

ferdi · Jul 31, 2016

toeslider said:
Welcome to the future Patrick. Bikes are becoming increasingly more tamper-proof thanks to all those well-meaning folk in the European parliament. The New Euro 4 regs even require diag plugs so that the police can make sure the ECU hasn't been 'hacked' when they pull you over. Our brave new Euro 4 world starts on January 1.

haha, new bikes all have diag plugs, that's no euro4 feature.

and, no one except factory can see and deside if a map is changed from original or not. there exist many maps for each model, from factory, so, this will be not possible for anyone except factory itself. i live in europe, and that police will check maps is bs, believe me. just for now. whats happening in some years, who knows ?

robbub · Jul 31, 2016

Wow! This is pretty crazy. The dealer put the 14T sprocket on mine when I picked it up new, and I've never had that issue (except when I took off the clutch switch).

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toeslider · Aug 3, 2016

Hey Ferdi, I know bikes come with diag plugs. The difference with Euro 4 is that they are now mandatory spefically so the police can do roadside inspections. Read the regs.

kuksul08 · Oct 17, 2016

Does anyone here have a 14T sprocket with the exhaust valve motor removed and not have any rev limiter issues that I described?

That's the last thing I can think of that could be causing some fault in the computer.

gatdammit · Oct 18, 2016

You have the RB Evo, right? Think the fueling and change in gearing messing with ECU reading could be the culprit?

kuksul08 · Oct 18, 2016

gatdammit said:
You have the RB Evo, right? Think the fueling and change in gearing messing with ECU reading could be the culprit?

Yeah I do. The bike shouldn't even know it's there...

hexanerax · Oct 18, 2016

Could it be the Traction control cutting in ? Second gear does have serious bite at 7K+ revs and your tire may not be holding that power down. Maybe try turning the DTC down or off for a test.

01101101 · Oct 18, 2016

hexanerax said:
Could it be the Traction control cutting in ? Second gear does have serious bite at 7K+ revs and your tire may not be holding that power down. Maybe try turning the DTC down or off for a test.

Interesting thought. I have seen the same issue with rev limit abruptly kicking in around 8000 rpm since switching to 14t. Sometimes however I can go above 8000 without issues. Could indeed depend on riding mode, it seems to be less frequent (or even gone) in sports mode where I have DTC 2.

kuksul08 · Oct 18, 2016

I turned DTC and ABS off completely. I also accelerated gently up to 7500RPM and then went to part-throttle and just carefully approached 8000 on a straight stretch of road. It cut in every time at 8000 with a rev limiter.

astrocortex · Oct 26, 2016

yo man

Is this still giving you a hard time? I was thinking - intermittent. What would intermittently cause this issue. It almost has to be the switch/sensor on the rear right side of the motor with the grey cover OR its your clutch switch acting funky.

If it were me, I would assume its the one that vibrates all the time on the backside of the engine. But in my case it was the clutch switch. It can be pretty easily figured out if you can just connect both the wires (no switch issues) or put a zip tie on the switch, leave it hanging and ride it for awhile.

Admittedly I feel like I already told you all this though? man im getting old LOL. I still havent put the replacement switch in for mine. Lazy I guess, but it works just fine. Only time its given me an issue is when I stall it at an intersection (2-3x so far) and for some reason whenever I stall it I magically cant find neutral(from the bikes perspective), even though its in neutral. After I kick at it 20-30 times and wave some cars by, it will just work. Kicking things. Thats how I fix everything.

kuksul08 · Oct 26, 2016

astrocortex said:
yo man

Is this still giving you a hard time? I was thinking - intermittent. What would intermittently cause this issue. It almost has to be the switch/sensor on the rear right side of the motor with the grey cover OR its your clutch switch acting funky.

If it were me, I would assume its the one that vibrates all the time on the backside of the engine. But in my case it was the clutch switch. It can be pretty easily figured out if you can just connect both the wires (no switch issues) or put a zip tie on the switch, leave it hanging and ride it for awhile.

Admittedly I feel like I already told you all this though? man im getting old LOL. I still havent put the replacement switch in for mine. Lazy I guess, but it works just fine. Only time its given me an issue is when I stall it at an intersection (2-3x so far) and for some reason whenever I stall it I magically cant find neutral(from the bikes perspective), even though its in neutral. After I kick at it 20-30 times and wave some cars by, it will just work. Kicking things. Thats how I fix everything.

It's not intermittent, it was very consistent. At first I thought it was intermittent, until I figured out that it only happened in 2nd gear, 8000RPM.

14T Front Sprocket Issues...?

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