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Hi,
I just followed the “How to do it” info in this mega thread.
Mine was a 2019 Pure.
No problems.
Cheers,Ken.
PS. The flapper on my 2020 model looks just the same.
Ok Ken, thank you very much.
I was concerne about the electrical connection. Isn't in a diferent place?
 

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2021 Scrambler and 2020 1250 GSA
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Ok Ken, thank you very much.
I was concerne about the electrical connection. Isn't in a diferent place?
Just disconnect the cables that control the flapper——not the wiring that controls the servo. Leave the servo right where it’s at and plugged in to the bike.
 

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2021 Scrambler and 2020 1250 GSA
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Posting these pics of the 2021 w flapper delete and the extra O2 sensor just for reference
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A0056DA2-43A5-4EFC-A01B-574AF96F8B9F.jpeg

Edit
That’s the servo that used to have cables coming out of it
 

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EDIT : The following procedure is for a quick and dirty disconnection, or destined to someone who doesn't care about keeping the cables attached to the flapper assembly or just wants to try it out. If you'd prefer a cleaner mod, do familiarize yourself with this post first then check out this post by @LWIRWA. His take on it keeps the plastic housing on the pipe, as it's welded in place anyway, but gets rid of the cables.

I offered member @RninetDOG to provide a tiny how-to guide regarding the disconnection of flap cables, so I thought that doing it here might be best.

Here we go :

0) We'll need a 10mm flat spanner as well as a ratchet wrench with a Torx T25 bit. Some thread-locker might be advisable.

1) Locate the two screws on the flap's plastic housing. One is visible from the side-stand side of the bike, the other one will be easier to reach from the other side. It's basically facing the ground, laying down will help. Remove them.

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2) Remove the plastic housing by sliding it towards you. You'll be greeted by this :

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On this picture one of the two little brass tabs is removed from its nest for illustration purposes. Use the 10mm spanner to unscrew the nuts which hold the cables to the metal housing. Pull the cables towards you. Push down on both of the brass tabs, they should dislocate easily and the cables spring straight out like this :

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4)

From there on it's already time to reassemble everything. Push the cables back in position and tighten the 10mm nuts, leaving the tabs hanging somewhere in the middle of the "cup" of the flap, as it'll be easier to then reinstall the plastic housing.

The screws which hold the plastic housing should have some threadlock on their thread. As mine were extremely easy to screw out and back in, I didn't bother to clean the threads and just applied a tiny amount of medium strength threadlock and tightened by hand.

That's all !

I couldn't recommend trying this solution out highly enough before any slip-on purchase or further modification. Totally reversible in mere minutes, very effective at bringing back some much-missed exhaust sound (especially at low revs / small throttle openings), and completely free to boot. It might be just enough for you, as it was for me. Do try it !
 

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Hello Euler's Identity, I too have a 2021 model R9T and have a few questions on you simple how to mod.

With both cables unhooked form the valve, how do you know in which position it is set to in the exhaust pipe?
Do you have to perform this while the engine is running?

Thank you.
 

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Hello Euler's Identity, I too have a 2021 model R9T and have a few questions on you simple how to mod.

With both cables unhooked form the valve, how do you know in which position it is set to in the exhaust pipe?
Do you have to perform this while the engine is running?

Thank you.
The valve/flapper assembly is designed to fail open, there's a spring that ensures that it remains so should the servos and cables fail to operate.

If you want to be sure, just do the whole mod with the silencer off the bike, the valve is just behind the tip of the linkpipe so you'll see it straight away.

No of course not, keep that engine off !

You're welcome :)
 

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BMW R NineT 2021 (Black Storm Metallic, Comfort Pack, Adaptive Headlight, Option 719 Classic Wheels)
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The valve/flapper assembly is designed to fail open, there's a spring that ensures that it remains so should the servos and cables fail to operate.

If you want to be sure, just do the whole mod with the silencer off the bike, the valve is just behind the tip of the linkpipe so you'll see it straight away.

No of course not, keep that engine off !

You're welcome :)
Just to jump in on this and thank Euler's Identity for taking the time to try this mod and document it for the rest of us. I did it yesterday evening, and WOW what a difference! That active flap is working hard as standard.

The sound seems to be very similar to my Euro3 model with a flap delete and baffles in, if anything a bit louder (which adds up because the larger diameter catalytic converter should be less restrictive, same for the larger diameter flap pipe). Throttle response is also crisper off the bottom and the bike really barks if you blip the throttle at tickover now, much more like what I expected. Best of all it retains the catalytic converter to keep Captain Planet happy, and outwardly looks completely unmodified.

Thanks Euler's Identity for saving me from spending £500 on some decat headers from unit garage which I would have likely found too loud :)
 

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Just to jump in on this and thank Euler's Identity for taking the time to try this mod and document it for the rest of us. I did it yesterday evening, and WOW what a difference! That active flap is working hard as standard.

The sound seems to be very similar to my Euro3 model with a flap delete and baffles in, if anything a bit louder (which adds up because the larger diameter catalytic converter should be less restrictive, same for the larger diameter flap pipe). Throttle response is also crisper off the bottom and the bike really barks if you blip the throttle at tickover now, much more like what I expected. Best of all it retains the catalytic converter to keep Captain Planet happy, and outwardly looks completely unmodified.

Thanks Euler's Identity for saving me from spending £500 on some decat headers from unit garage which I would have likely found too loud :)
Thank you @FSEngineer, it's nice to have some feedback, it could incite the fence-sitters to actually go ahead and try it.

The only thing it doesn't do is bring the pops and crackles back, but that's surely a vain pursuit anyway. The cam change on the Euro 5 engine (less overlap) seems to have cleaned up hydrocarbons emissions big time.

I agree about the bark, surely the most pleasant improvement. I blip while filtering in town, and the bike used to sound quite pathetically asthmatic with the valve in operation.

You're welcome :)
 

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BMW R NineT 2021 (Black Storm Metallic, Comfort Pack, Adaptive Headlight, Option 719 Classic Wheels)
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The only thing it doesn't do is bring the pops and crackles back, but that's surely a vain pursuit anyway. The cam change on the Euro 5 engine (less overlap) seems to have cleaned up hydrocarbons emissions big time.
If the catalytic converter is doing it's job then there shouldn't really be any pops or crackles from unburnt fuel in the exhaust, but I do get the odd burble rolling off the throttle at low speed/RPM. I'll have to do a bit more riding to get a good measure of the sound improvement, thankfully England are playing another match in the Euros at 8pm today so the roads will be nice and empty for an hour and a half :D
 

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If the catalytic converter is doing it's job then there shouldn't really be any pops or crackles from unburnt fuel in the exhaust, but I do get the odd burble rolling off the throttle at low speed/RPM. I'll have to do a bit more riding to get a good measure of the sound improvement, thankfully England are playing another match in the Euros at 8pm today so the roads will be nice and empty for an hour and a half :D
Well I suppose that unburnt fuel ignites upstream from the cat, and the ensuing shockwave then travels through the cat and pipe.

My euro 4 Pure used to be quite expressive on the overrun, and that's the only thing I really miss from it. I do miss that quite a bit though.

Using a football match to get some free road space, now that's a strategy I can subscribe to.
Finally, someone found a use for that sport... ;-)
 

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BMW R NineT 2021 (Black Storm Metallic, Comfort Pack, Adaptive Headlight, Option 719 Classic Wheels)
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My euro 4 Pure used to be quite expressive on the overrun, and that's the only thing I really miss from it. I do miss that quite a bit though.
Strangely my Euro 3 was never that excitable, you really had to work to make it pop (even with remus decat headers and a Hilltop remap) unless it was very hot. It did burble a bit though.
 

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Strangely my Euro 3 was never that excitable, you really had to work to make it pop (even with remus decat headers and a Hilltop remap) unless it was very hot. It did burble a bit though.
Pures and Racers have the reputation of being more expressive than Standards because of their pipe, but I don't think that even the heavy twin pipes could muffle pops and bangs to that degree. Mine sounded healthy, but low to low-mid overruns from a full throttle were absolutely glorious. No disgusting leaned-out automatic rifle shots like old bandit 600s wearing 50p Ebay slip ons, just good old pops that a Chevy short block wouldn't disown. Makes me a bit melancholic actually to think about that.

Does it get through that I'm a bit (just a bit) of an engine man ?
 

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Pures and Racers have the reputation of being more expressive than Standards because of their pipe, but I don't think that even the heavy twin pipes could muffle pops and bangs to that degree. Mine sounded healthy, but low to low-mid overruns from a full throttle were absolutely glorious. No disgusting leaned-out automatic rifle shots like old bandit 600s wearing 50p Ebay slip ons, just good old pops that a Chevy short block wouldn't disown. Makes me a bit melancholic actually to think about that.

Does it get through that I'm a bit (just a bit) of an engine man ?
Strange! I did notice that the Euro 5 Scrambler I had as a courtesy bike last week was louder than mine, so it makes sense that the different end cans do make a big difference.

Nothing wrong with being an engine man, I do enjoy that the engine in the R9T at 94ps/litre has one of the highest (if not the highest?) specific outputs of any production air-cooled engine
 

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Peeps, if your bike is getting a bit rusty and you still have the flappy valve then please check that it hasn’t seized solid like mine did. The bike’s computer has no idea of what’s going on back there, it sends the flappy signals but can’t check if it worked. Mine seized up at 45’ a long time ago and it made such a difference when I removed it.
 
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I've been pissing about with my flapper valve for a few weeks now and I had reinstalled the flapper because I am sure it has more torque with it, maybe its something to do with back pressure.

The thing I decided I couldn't live with however, was the very obvious on and off of the volume coming through the exhaust when the flapper is working. It's clearly also a noise control device and it ended up pissing me off so I took it out again.

The bike seems to spin up more easily without but it definitely has less shove below 3500rpm. (mine does anyway - 2014). It's fast enough and I prefer the sound this way with the pops and bangs on the overrun so it'll stay like that now.
 
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