Exhaust flapper valve does not cycle at ignition ON.

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Casbar
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Casbar »

GuyRT wrote:
I'm not sure if it's even necessary to fit a Healtech.


As far as I can see if you were to disconnect the cables from the exhaust valve and leave them free so that the solenoid still moves them, the bike has no way of knowing whether the valve flap is moving or not.


There are no sensors after the valve or attached to the valve itself.


I suspect the bike only throws a code when there's an excess current load caused by the solenoid where the valve is sticking?


The exhaust valve flap should spring open by default and so long as it can be moved into the open position with the cables disconnected it should stay there.


I suspect the bike will then run fine without throwing any codes.


I'll find out for sure if this is actually the case once my bike is out of warranty, the first time the valve sticks because this will be my first move!

Nope it is not the case. If you just disconnect the cables, the solenoid will still throw an error code. The spring on the top of the valve resets the valve to open and the solenoid so the solenoid pulls the valve to closed but the spring pushes it back to open. If on a pre 1250 there will be an error but no visible warning lights. On the 1250 there is an orange engine warning light when the valve is stuck. The only way to sort is - new headers, or clear code with a GS911 and fit a servo buddy to fool the ecu.
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sakm
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by sakm »

Casbar wrote:
Nope it is not the case. If you just disconnect the cables, the solenoid will still throw an error code. The spring on the top of the valve resets the valve to open and the solenoid so the solenoid pulls the valve to closed but the spring pushes it back to open. If on a pre 1250 there will be an error but no visible warning lights. On the 1250 there is an orange engine warning light when the valve is stuck. The only way to sort is - new headers, or clear code with a GS911 and fit a servo buddy to fool the ecu.

Are you sure?


I am pretty sure I have read that people have just disconnected the cables and all was well


I also exercised mine with the gs-911 while the exhaust was off and I am pretty sure I could physically see the motor pulling on both cables to try and move it each way when it was seized up
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Casbar »

sakm wrote:
Are you sure?


I am pretty sure I have read that people have just disconnected the cables and all was well


I also exercised mine with the gs-911 while the exhaust was off and I am pretty sure I could physically see the motor pulling on both cables to try and move it each way when it was seized up

I messed around a lot with this a few years ago. I disconnected the cables and the servo on its own still threw an error code. The spring is strong, so if the servo is push and pulling, it is pulling against the spring, which I agree it does, but the spring is resetting the flap, so I thought the servo was only activating and spinning in one direction, not both. If just disconnecting the cables worked, then there would be no requirement for the servo buddy to fool the ECU. But we only have on 2015 bike left in the fleet and the flap is stuck open, there are no dash warning lights, so it has been left. Mine and the rest of the fleet are 1250s, so I haven't bothered investigating any further as the bikes have all had new headers, will do something about it, once the bikes are out of warranty and if the engine warning light comes on. So no, not 100% sure as it has been a while :)
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by sakm »

Casbar wrote:
I messed around a lot with this a few years ago. I disconnected the cables and the servo on its own still threw an error code. The spring is strong, so if the servo is push and pulling, it is pulling against the spring, which I agree it does, but the spring is resetting the flap, so I thought the servo was only activating and spinning in one direction, not both. If just disconnecting the cables worked, then there would be no requirement for the servo buddy to fool the ECU. But we only have on 2015 bike left in the fleet and the flap is stuck open, there are no dash warning lights, so it has been left. Mine and the rest of the fleet are 1250s, so I haven't bothered investigating any further as the bikes have all had new headers, will do something about it, once the bikes are out of warranty and if the engine warning light comes on. So no, not 100% sure as it has been a while :)

I still have all the parts so when I get spare time I can easily do a few tests and see whats going on for sure


When I was messing with mine I could have sworn the cables pull either way but can't be positive!


I just thought sod it for £40 the servo buddy just removes the lot and its job done
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Casbar »

It would be good to see if cables removed, if the servo still throws an error. But as I said, not a priority for me at the moment, as all is good on the bikes :)


On UKGSER some chap has said he programmed the ECU to stop closing the valve, not sure if you can do this with a GS911, but that sounds a great idea :)
Last edited by Casbar on Sun Jul 17, 2022 4:34 pm, edited 1 time in total.
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7vwh
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by 7vwh »

My flap seized so I freed it up for it to seize again. I disconnected the cables from the flap end. On ignition ‘on’ both cables cycle/move alternately as a test. 2014 so no warning on the dash but an error listed on the GS911.
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Casbar »

7vwh wrote: My flap seized so I freed it up for it to seize again. I disconnected the cables from the flap end. On ignition ‘on’ both cables cycle/move alternately as a test. 2014 so no warning on the dash but an error listed on the GS911.

It is only 1250s on that show an orange warning light on the dash, not earlier bikes
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GuyRT
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by GuyRT »

sakm wrote:
I still have all the parts so when I get spare time I can easily do a few tests and see what's going on for sure


When I was messing with mine I could have sworn the cables pull either way but can't be positive!


I just thought sod it for £40 the servo buddy just removes the lot and its job done

Interesting!


This is where I'm at as well, my bike is still in warranty but once it is out of warranty if the valve sticks then this is when I'll investigate a bit further.


So really then, it's one cable to close the valve and the second cable is only really there to actuate a switch on the servo unit to let the bike know when it has sprung to the open position again, that is if if I've understood this all correctly.







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mondeoman
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by mondeoman »

Here's my two penneth, 1250 2020 RT , 8500 miles, MIL light comes on and stays on, muffler off and can see flap only partial movement, independent BMW specialist removes cables, set the flap fully open and knocks off the light, ride home about 40 miles and light stays off, great !!,  later same day nip to town 10 miles and lo and behold light is on again and stays on.
refit cables and book a warranty claim, headers/cables/cat' etc , BMW main dealer fit all new no problem, light is off , my 3 year warranty is up next April and with the price of the aforementioned parts now at something approaching £1500/£1600 it's a bit of a concern.
Last edited by mondeoman on Mon Jul 18, 2022 10:07 am, edited 1 time in total.
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by GuyRT »

mondeoman wrote: Here's my two penneth, 1250 2020 RT , 8500 miles, MIL light comes on and stays on, muffler off and can see flap only partial movement, independent BMW specialist removes cables, set the flap fully open and knocks off the light, ride home about 40 miles and light stays off, great !!,  later same day nip to town 10 miles and lo and behold light is on again and stays on.
refit cables and book a warranty claim, headers/cables/cat' etc , BMW main dealer fit all new no problem, light is off , my 3 year warranty is up next April and with the price of the aforementioned parts now at something approaching £1500/£1600 it's a bit of a concern.

That tends to confirm it then, removing the cables will not stop it throwing a code. :sueno:


Removing the servo and fitting a Healtech unit seems to be the way forward then once the bike is out of warranty.
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Levisp
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Levisp »

mondeoman wrote: Here's my two penneth, 1250 2020 RT , 8500 miles, MIL light comes on and stays on, muffler off and can see flap only partial movement, independent BMW specialist removes cables, set the flap fully open and knocks off the light, ride home about 40 miles and light stays off, great !!,  later same day nip to town 10 miles and lo and behold light is on again and stays on.
refit cables and book a warranty claim, headers/cables/cat' etc , BMW main dealer fit all new no problem, light is off , my 3 year warranty is up next April and with the price of the aforementioned parts now at something approaching £1500/£1600 it's a bit of a concern.

If the valve is stuck then it maybe better to leave the cables off so the motor can freely move. Servo motor trying to work against a stuck valve may not be a good idea. Have you tried to unstick the valve ? I have only experienced a struck valve once and was able to free it and have had no problems since. What I did was remove end can, covers and cables. Stuff a rag down the exhaust passed the valve to protect CAT. Then I applied WD40 to the valve spindle top and bottom. Let this soak in for an hour and reapply. Then I used a large screwdriver as a lever to work the valve back and forth. Initially very stiff but gradually it started to free up. Left over night and the next morning repeated WD40 and eventually was able to get the valve to move really easily. Could be worth a try.
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Casbar »

Been there and got the T shirt with respect to lubing the flap spindle and top. Quick back story, 2014 bike, two sets of headers over 30k miles. 1250RT, new headers at 5k miles, on this bike, I regularly lubed the spindle with special high temp grease (recommended on a US forum). Made no difference at all.


2015 RTp flap stuck at or before 30k, freed off and lubed with same high temp lube, lasts about 3 months before it is stuck again, now stuck open and left, bike has now done 57k. This is a fleet bike. 3 other 1250s, ranging from 2019 to 2021 bikes, all have now had new headers.


I have at least 3 mates on 21 and 22 bikes, all have had new headers.


BMW insured warranty does not cover this issue! So when mine stick again, I'll use a GS911 to get rid of light and fit something like a servo buddy and disconnect the cables. But if you can stop the ECU trying to close the flap even better :)


Or trade the bike and buy a new one :)



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Levisp
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Levisp »

Has anyone checked the free movement on a new bike / replacement system ? This stupid valve should move freely but I wonder if it does out of the factory. However as you say if the problem persists then servo buddy thingy is the answer.
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mondeoman
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by mondeoman »

mondeoman wrote: Here's my two penneth, 1250 2020 RT , 8500 miles, MIL light comes on and stays on, muffler off and can see flap only partial movement, independent BMW specialist removes cables, set the flap fully open and knocks off the light, ride home about 40 miles and light stays off, great !!,  later same day nip to town 10 miles and lo and behold light is on again and stays on.
refit cables and book a warranty claim, headers/cables/cat' etc , BMW main dealer fit all new no problem, light is off , my 3 year warranty is up next April and with the price of the aforementioned parts now at something approaching £1500/£1600 it's a bit of a concern.

Further to this, my Indy' BMW specialist stated that disconnecting the cables and knocking the light off normally light stays off but best theory is that the servo motor having been heaving against the semi seized flap, the motor itself is knackered hence the light coming on again.
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Re: Exhaust flapper valve does not cycle at ignition ON.

Post by Casbar »

Took one of our bikes to a new Motorrad Dealer on Friday, told him the flap was stuck on another of our 1250s. He said, they are obviously not ridden hard enough, as its carbon build up. I told him that is crap and asked him how long he had been working as a BMW Motorrad Service manager, he replied he hasn't they were a car dealership that has just converted  8)  But the mechanic was really good and did a great job on the 12k service
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