Exhaust flap

General discussion of the BMW R1200RT/R1250RT
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Beagle
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Re: Exhaust flap

Post by Beagle »

Theres some vids on youtube on how to deal with it.
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Beagle
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Re: Exhaust flap

Post by Beagle »

Would this help applied to pivot points?

Exhaust temp can be 1200 degrees F at the headers.


It must be a lot less where the Flapper valve is surely?

https://www.superior-industries.com/dsf_5000_product_122.html
Last edited by Beagle on Fri Sep 21, 2018 6:20 pm, edited 1 time in total.
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Levisp
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Re: Exhaust flap

Post by Levisp »

Beagle wrote: Would this help applied to pivot points?

Exhaust temp can be 1200 degrees F at the headers.


It must be a lot less where the Flapper valve is surely?

https://www.superior-industries.com/dsf_5000_product_122.html

Nice idea but how do you get to the pivot to lube. Don't think it comes part. If anyone knows better please share.
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Beagle
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Re: Exhaust flap

Post by Beagle »

https://m.youtube.com/watch?v=8sMd6rxOY2I


I fit an Akrapovic silencer recently and saw the valve when I removed the original. Arent the pivot points visible then?
Casbar
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Re: Exhaust flap

Post by Casbar »

You can't take it apart, but you can see it if you take off the silencer. Don't think squirting stuff on it helps much, once the pivot is worn your onto a loser.
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Beagle
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Re: Exhaust flap

Post by Beagle »

I dont believe wear is the problem in fact the opposite. Carbon buildup and corrosion leads to seizure.
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Levisp
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Re: Exhaust flap

Post by Levisp »

Yes you can certainly see the flap and pivot when you take the silencer off. However the actual bearing surfaces that the pivot moves could only be lubed if you can get at them. The bottom of the pivot underneath the pipe is capped. I cannot see how you can take it apart to grease it. The best you could do is squirt something on it from the inside but as a previous post states I very much doubt it would do anything. Basically its a bloody useless design. The other solution to a seized flap apart from replacing the exhaust pipe would be to take it off and find an exhaust fabricator to cut it off and weld a connecting piece without flap in its place. Think there are ways around spending huge amounts of money on a new exhaust for it to only happen again some time in the future.
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Levisp
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Re: Exhaust flap

Post by Levisp »

If BMW cannot make an exhaust flap last lets hope the engineer who is responsible for the more complicated valve mechanism has got it right. Good luck to anyone who buys the latest and greatest next year.
Sethmopp
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Re: Exhaust flap

Post by Sethmopp »

I think Black Widow make alternate headers that seem to dispense with the valve, they're about £315 on fleabay.
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Levisp
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Re: Exhaust flap

Post by Levisp »

Sethmopp wrote: I think Black Widow make alternate headers that seem to dispense with the valve, they're about £315 on fleabay.

Thanks for info nice one.


https://www.blackwidowexhausts.co.uk/bm ... 3792-p.asp


If mine goes this is what I will do. Only thought is would the bike need re-mapping. However if it does still cheaper than OEM replacement.
B787MECH
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Re: Exhaust flap

Post by B787MECH »

Levisp wrote:
Thanks for info nice one.


https://www.blackwidowexhausts.co.uk/bm ... 3792-p.asp


If mine goes this is what I will do. Only thought is would the bike need re-mapping. However if it does still cheaper than OEM replacement.
Interesting link, although the problem of the valve actuator would still need to be addressed as it would probably detect a fault. The guys at https://www.healtech-electronics.com/products/ese/ seem to make a servo eliminator but you'd have to confirm it fits the LC.


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Levisp
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Re: Exhaust flap

Post by Levisp »

Interesting. However I think if you leave the motor connected but just remove the cables then the system sees no fault because the actuator motor is still working. If someone has done this maybe they can confirm it.
B787MECH
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Re: Exhaust flap

Post by B787MECH »

Levisp wrote: Interesting. However I think if you leave the motor connected but just remove the cables then the system sees no fault because the actuator motor is still working. If someone has done this maybe they can confirm it.
I share your logic but going on previous experience (on a Aprilia) simply removing the cables is not the end of the story as the actuator runs past its normal limit and throws up a fault.


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Casbar
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Re: Exhaust flap

Post by Casbar »

Well Mr BMW has agreed to replace the exhaust again. So I am taking it in on Friday as it needs to be done before my warranty runs out on the 4th Oct. 2014 bike, 17k and will now be on my second set of headers.
kioolt
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Re: Exhaust flap

Post by kioolt »

Here's a company that makes a device that fools the ECU into thinking the servo is still connected.


https://www.skutr.net/exhaust-valves-an ... explained/


They also have an explanation of what the exhaust flap is for.
The cheapest thing on a BMW is the nut that connects the handlebars to the seat.
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