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cst,

Some guys have cut out the valve.

This thread deals with disconnecting the valve control.
The servo adjusts the valve between ~3K & 5K RPM.

There is a spring on the valve that holds it at
the inactive position outside that RPM range.


Here is my latest mod to disable the valve, at the servo wheel.
Shrink wrapped 4mm-0.07 bolts.

I've heard of no one who has actually confirmed, via a dyno, the results of this mod.
 

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You can modify the Valve actuator but you have to leave the lambda (oxygen) sensor plugged in with the factory ECU otherwise you'll get an error code. I've got the slip on ECU so I'll can ditch the lambda and the actualtor cables aswell. Sweet mod. Thanks guys...
 

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I tried this fix too

Gents, I just tried this fix too. I had the fairing off already from trying several things to make this bike run ACCEPTABLE below 4 grand. the whole job took 20 minutes. It is acceptable, but that is it. It is a 75% solution for my bike,with slip-ons. Like my 1990 750 sport was back then. Then my 92 851 was back then. But they were almost 20 years ago, and these things should work way better by now. I had a 916, 996, 998, 999, and none of them were this rough even after this fix. So, even though the cables are un- hooked and the small flat stock bracket replacing the cable pulley is fooling the ecu, does the computer send a richer or leaner signal for a moment ,when it was SUPPOSED to open that valve? And if so, does that happen in conjunction with the position of the shaft on the servo? If i re-adjust the position of the flat stock on the shaft ,will it improve the low end roughness? I bought a power commander, but I dont think i want to waste my time with it if it wont help smooth out the bottom end. Do you thik this is as good as it will get? The 999 i am selling is SOOOO sweet at mid and lower rpms. But the 1098 is much nicer EVERYWHERE else. Any ideas? cheers, kent from addams autocycle
 

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Ive done this mod and had no problems,Seems to run better with the flapper disabled.
From what I understand the flapper is for noise emisions only, the fueling at the lower rpms is done by the o2 sensor.
I dont think the two are related, but could be wrong!

Doon
 

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After reading this thread and several like it I performed the Exhaust Flapper Mod. When I was finished I realized there is a much easier way to get this done without removing the entire right side fairing.

In the end, all I did was removed the heat shield that covers the flapper valve. Since the flapper is biased open, I just removed the upper cable from the actuator and fitted a spring over the exposed end of the cable to keep tension on it. Now the flapper stays open at all times, and the ECU thinks everything is normal.

I just found this to be much easier that messing around and retro-fitting the actuator located under the fairing.

The entire process took about 10 minutes to complete. So far it works perfect and sounds better than my friends stock 1098.
 

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I take it a Race ECU does not have the provisions for the exhaust valve? I mean, if you had a Race ECU, you could simply pull the servo and valve without any CEL Coding, warning lights etc. and still be fine?
 

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The way I understand it, the Termi Slip-On kit comes with an ECU that tells the computer to keep the valve open at all times. If you get a full Termi system, the valve is gone all together.

My next project is to "Core" my stock exhaust. Does anyone have any info. on how to do this?
 

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Search my man.... search. There was a thread by 'crasyste' (?) (Alfredo's young fella) with some refinements by another member on this forum.

I could link it for you...... but that would take the fun out of it for you :p Happy hunting and coring
 

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After reading this thread and several like it I performed the Exhaust Flapper Mod. When I was finished I realized there is a much easier way to get this done without removing the entire right side fairing.

In the end, all I did was removed the heat shield that covers the flapper valve. Since the flapper is biased open, I just removed the upper cable from the actuator and fitted a spring over the exposed end of the cable to keep tension on it. Now the flapper stays open at all times, and the ECU thinks everything is normal.

I just found this to be much easier that messing around and retro-fitting the actuator located under the fairing.

The entire process took about 10 minutes to complete. So far it works perfect and sounds better than my friends stock 1098.
Could you post pics and explain how to do this in more depth?
 

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After lots of reading up on the subject and getting not much more than a bunch of unanswered questions I decided to attempt it myself. For those of you with stock exhaust or slip-ons without a Ducati ECM (which is supposed to cure this problem) this is the solution I came up with. I just got back from a 30 mile ride and no CEL.

The main thing I learned is that by removing the cables... you get a CEL. By removing the pulley, you get a CEL. When you turn the key on the servo goes all the way one way and then back the other way, from what I can gather it does this to learn where the end-points are every time you power the bike up. Without cables or a pulley it will spin all the way around freely until it "times out" and the CEL comes on because it thinks a cable is broken. So, as long as the servo is stopped by something very closely to the same points it stops at when hooked up to the valve, it thinks everything is fine and it goes to the open position and patiently waits to mess up your sound and mixture around 3000rpm as usual.

Here is what worked for me...

I started by removing the the cables from the servo side of things, as long as the servo is all the way one way or the other you can pull down on the loose cable enough to slide it out of its holder and then disengage the cable itself from the pulley.

You can then manually turn the servo the other way using a large wrench on hex shaped outter end of it, I did this slowly as to not strip out the gears. **Make sure the key is OFF, if the key is ON the servo will not move and you will ruin it!!** After you turn it the opposite direction you can remove the other cable from the pulley.

After that I re-centered the pully so it was pointing straight up and removed it, hold it with a wrench, remove the bolt and you can pull it off by hand.

Next I cut a piece of aluminum flat stock and drilled a hole in the center and mounted it tightly to the shaft using a star washer on the back side and a lock washer on the front. Probably a good idea to put a drop of red Loctite on the nut too.



Make sure that when you put the aluminum (or metal or carbon or whatever you decide to use) piece on you make sure that the top and bottom edge of the flat on it are perpendicular to the flats cut on the shaft of the servo. The round sides of the shaft should be facing up and down respectively after the part is installed when viewing from the end of the shaft.

The idea is that the piece be long enough to come in contact with the plastic cable holding bracket on the bottom of the servo case, therefore stoping the servo at almost exactly the same point on each side, as if it were hooked to the valve.

Once the part is installed, I turned my key on to test it... if its out of position or wont let it go far enough one way or the other, you'll get a CEL before you even start the bike. I then turned the key off, made a small change and tried it again until I got no CEL. My CEL seems to reset itself after I turn the key off and wait a couple minutes.

Once I got this working correctly I took some small wheel collars from Radio Controlled aircraft/cars/helicopters etc... made by a company called Dubro and can be found at any hobby store, and cut a small groove on one side with a cut-off wheel in my dremel so I could slip it over the cable without cutting the ends off and ruining the cable, if for whatever reason I may want to hook it back up again I didnt want to have to buy new cables.







These have a small allen head set screw in the side of them for tightening onto a piece of metal rod or cable...



Once I notched the side, I pulled the slack out of the cables on the servo side and put these little guys on the cable above the mount to keep the cable sleeve from falling out of the servo mounting tab and rattling around under my fairings. The spring on the exhaust valve will hold the valve in the open position so pulling the slack out and putting these on basically ensure that the cables stay put. I suppose you could take them off at this point but seeing I wasnt sure if this was going to work, I left mine on.

Mine looks like this with the collars installed...



Here is a picture of it at rest with the key on, you can see the aluminum is almost resting on the plastic cable holder on the right side, this is what limits the movement, it hits the plastic and then springs back a touch. I hits the same spot on the other side, with a straight piece roughly this size these stop points are within a couple degrees of the cable stop points.




Only thing to watch for is that you dont make the part any longer than it needs to be or taller on the top sides opposite of what hits the plastic as it could contact the inside of the fairing once reinstalled through its course of movement if its too big. The servo will still move, thinking its opening and closing the valve while you ride but set up like this, it seems to trick it just fine and best of all, when done properly you should get no CEL.

My piece is a bit crude looking, I cut it out with a dremel and didnt finish it nicely because it was basically an experiment. Not that you can see it under the fairing anyways :)

The bike is throatier through the normal cruising rpm range of 3K-5Krpm with the valve disconnected and seems to run smoother while at a cruise in town within those rpm ranges. It also seemed to get rid of that little flat spot around the same rpm when accelerating from a stop.

If I find anything else worth noting I will update but so far all seems well! Exhaust vavle free! :)
Can I get the dimentions to this part, so I can pre-fab the part to take to the shop when they do the Leo Vince Full System install. My 848 is at the shop so I cant do the measurements my self.
 

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the shop should be able to easily do it. It took me 5 minutes to fab up the piece. It just needs to be just long enough to hit the corner of the plastic. An easy way to install it would be to start the bike in diag. mode (push the display toggle up turn the key while holding it up until the display appears with a reprogram mode) then scroll until you get the exhaust valve mode... This allows you to move the valve with the switch to your desired spot. I used this to remove the cables (which is what you are supposed to do anyways) and then to position the servo in the middle.
 

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people people people, I did fit a full zard system on the weekend and without modifying the servo at all I have no error codes!!! The trick is to remove the cable from the flapper side with out turning the pulley on the servo at all!!! You will not get any error codes at all. I did it and it works. I was told this info by my zard dealer and to my disbelief it worked.
 
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