Exhaust flap

General discussion of the BMW R1200RT/R1250RT
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smileymiley
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Exhaust flap

Post by smileymiley »

Just had the end of warranty check today, exhaust flap has seized!  Looks like new set of pipes again. 15500 miles.
Had the exhaust system replaced on my 14 RT for the same problem.It's a pi@# poor design....
Vini, Vidi, Velcro....... I came, I saw, I stuck around.
guest4915

Re: Exhaust flap

Post by guest4915 »

smileymiley wrote: Just had the end of warranty check today, exhaust flap has seized!  Looks like new set of pipes again. 15500 miles.
Had the exhaust system replaced on my 14 RT for the same problem.It's a pi@# poor design....

Seems like a common problem. I intend to fettle mine every rear tyre change and switch the ignition on occasionally when I'm not using her so much in the winter months.
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Levisp
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Re: Exhaust flap

Post by Levisp »

I clean mine regularly in winter and paint a small amount of ACF50 on it. Never let it get too dirty. So far no issues. Either my maintenance is working or Im luck. Who knows. What annoys me is that this is a known problem and BMW just ignore it. I bet the new 2019 bike will have the same single exhaust downpipe design. Crazy !
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smileymiley
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Re: Exhaust flap

Post by smileymiley »

Levisp wrote: I clean mine regularly in winter and paint a small amount of ACF50 on it. Never let it get too dirty. So far no issues. Either my maintenance is working or Im luck. Who knows. What annoys me is that this is a known problem and BMW just ignore it. I bet the new 2019 bike will have the same single exhaust downpipe design. Crazy !
Mine is cleaned regularly, plastic cover removed & all cleaned, lubed. Its the internal pivot that has seized up tho. Not sure what you can put on this to keep it free given the harsh life it leads eg temperature etc.
Vini, Vidi, Velcro....... I came, I saw, I stuck around.
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Levisp
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Re: Exhaust flap

Post by Levisp »

Agree. I'm not sure what you can do as far as the internal pivot. It must get bloody hot. I always assumed that seizing problems were caused by external corrosion. In your case obviously not. I just wish that BMW had stuck to the previous model design then at least you could replace it with a sleeve with no valve. If mine goes then I will disconnect cables from motor and force valve open that will be something to look forward to.
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Beagle
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Re: Exhaust flap

Post by Beagle »

I was told by dealer that if they went wrong it was always in the open position. Obviously not?
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Levisp
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Re: Exhaust flap

Post by Levisp »

Beagle wrote: I was told by dealer that if they went wrong it was always in the open position. Obviously not?

They could be right. However I see no reason why if they fail they would fail always open. Surely the valve could fail at any point in its range of operation. But with BMW who knows.
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Re: Exhaust flap

Post by Casbar »

Same issue, had mine replaced nearly 2 years ago, its now squeaking again, so going to fail. Mine is under warranty as I paid a contribution towards it the first time, but dealer says they have to ask BMW if they can replace as it hasn't failed. The reason they normally fail in the open position is because open is the resting position and they generally fail when they have been sitting.
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Beagle
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Re: Exhaust flap

Post by Beagle »

Dealer implied if it fails open it isnt detremental. Got to ask if thats the case why is it there.
MEM62
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Re: Exhaust flap

Post by MEM62 »

Beagle wrote: Dealer implied if it fails open it isnt detremental. Got to ask if thats the case why is it there.
For the difference it makes in exhaust sound.   
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Sprintgull
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Re: Exhaust flap

Post by Sprintgull »

OK, maybe I'm being thick here.... why not simply remove it?
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Beagle
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Re: Exhaust flap

Post by Beagle »

We need to know why its there.


Apparently,


An exhaust flap in front of the muffler is actuated by an electronically controlled servomoter via a cable. This constantly adjusts the internal diameter of the exhaust system to suit engine revs and ensures good low to mid-range performance for a linear power output all the way to the rev limiter.
Last edited by Beagle on Fri Sep 21, 2018 12:52 pm, edited 1 time in total.
Casbar
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Re: Exhaust flap

Post by Casbar »

Sprintgull wrote: OK, maybe I'm being thick here.... why not simply remove it?

You can, but if you leave the cables attached and its seized, a fault code is generated when the bike is plugged into the computer, so BMW will know and at circa £1200 to fix, because it needs new headers an expensive repair. So if its stuck and they won't replace it, either move the cables so the servo still operates or bosh it out :) Of course, would you tell a prospective buyer? Mines not seized yet, but when it starts to squeak, it will seize at some point in the future.
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smileymiley
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Re: Exhaust flap

Post by smileymiley »

Beagle wrote: We need to know why its there.


Apparently,


An exhaust flap in front of the muffler is actuated by an electronically controlled servomoter via a cable. This constantly adjusts the internal diameter of the exhaust system to suit engine revs and ensures good low to mid-range performance for a linear power output all the way to the rev limiter.[/font]
That's part of it but aren't they also there to pass the noise regs at 5000 revs?
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Levisp
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Re: Exhaust flap

Post by Levisp »

I was under the impression it was for noise regulations. If mine seizes I will disconnect cables and see if it actually effects performance. If it doesn't then I have the option to leave as is or maybe buy a new exhaust system that gets rid of the valve and CAT and get it re-mapped. Then its cured for good. :)
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