Exhaust Servo Motor Failure

2737 Views 37 Replies 18 Participants Last post by joeducati, 2 mo ago

Audi403

Discussion Starter · 4 mo ago (Edited)

Hey guys,

I noticed a couple months ago that my exhaust flap wasn't working. I assumed it was going to be a seized flapper valve and planned to work it free when I got a chance. Today, I pulled the silencer off to have a look. I could move the flapper very slightly, but not much. I turned on the ignition to attempt the self-test, nothing happens. I connected with my GS-911 and ran the exhaust flap test. The Hex software told me that the output actuation completed successfully, but still no movement on the flapper. I removed the cables from the valve going to the servo motor. I tried rotating the flap, and to my surprise, it rotated completely free. I can spin it all the way closed with zero effort, and when I release it, it snaps back. I turned on the ignition again to see if I'd get any movement from the servo motor with it disconnected, nothing. Next, I pulled the servo unit from the bike and opened it up. I tried rotating the pulley inside of the servo unit with all my might, no movement. I'm not sure if this should be able to spin by hand or not...

Anyways, it sounds like my servo motor is shot. Would you guys agree? The only other thing I can think of trying is to find a wiring diagram and make sure I have voltage at the plug. Not sure if this is worth doing or not. I'm not even sure where to find a wiring diagram, can anyone point me in the right direction? I'll take a look in the service manual to see if I can find anything.

According to Healtech and multiple sources online, "the exhaust flap valve is designed to improve low down torque with the hindering of the flow of escaping gasses creating back pressure in the exhaust system". Even Akrapovic is putting valves on their headers for the R1250RT now. They say it is for improved rideability in lower RPM. I've read of many people removing these on their Wetheads and noting that they noticed no difference in performance. Many claim it is just for noise reduction. I ran a Servo Eliminator on my previous Ducati and had no issues. Thoughts?

It looks like the servo motor is around 300USD brand new. The only one I was able to find on eBay will cost around 250USD with shipping to Canada. Healtech makes a Servo Eliminator for our bikes and it's worth about 60USD.

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21 - 38 of 38 Posts

Mellow

· #21 · 3 mo ago

LAF said:
Well if it was me I would put a set of headers on and be done.

I use Akrapovic headers and do not miss the flap at all. It's whole function is noise abatement and nothing more. You can buy a Servo Buddy and that takes care of the dash light when not having that mess on your exhaust.

Nice... I like how you have your Denali lights pointed towards them to show them off...

Centerstand shield? Purpose? Thoughts?

nh1200c

· #22 · 3 mo ago

Barrie said:
My flapper valve is stuck and engine warning light is on. When I opened it up to see if there was any movement on turning on ignition, some times it tries to move and other times it doesn't. According to BMW Motorrad, mine has had two replacements already. Not good if it costs £1500 a time.

Hi Barrie -

I am having this issue to a slightly lesser extent on my 2020 R1250RT. Sometimes seeing partial movement at power-on, sometimes not. I am lucky that my bike is still in warranty, and even luckier that I have purchased the extended warranty so from the replacement standpoint I should be in better shape than many.

However, when I contacted my dealer (Max BMW) the service manager said they normally try to lubricate the valve prior to ordering a new exhaust. Since I had the bike in my garage for the 20,000 km service I thought I would give the lubrication a try. Of note on the partial movement issue for me was that my bike service area is still pretty chilly (~43F/6C) as we are just now getting some spring weather. While I was lubricating the valve it occurred to me that there could also be a temperature effect going on since the lack of movement was taking place prior to engine start.

Long story a bit shorter, the valve operated much better after the engine had warmed up the system, and I assume the spray on dry film lubricant might have also helped. Here is a video of the valve in operation afterwards.

The lubrication product that I used was: DuPont Non-Stick Dry Film Lubricant (https://www.amazon.com/gp/product/B003UTX0R8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1).

At the conclusion of all this, my GS-911 scans were clean and no longer showing the two Exhaust Flapper codes I had seen prior to service. (Mechanical Fault or Blockage and/or Adjustment Error)

Good luck!

Larry

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Mellow

· #23 · 3 mo ago

Seems like a good idea to spray some lubricant at that during every tire change since you are pulling the exhaust off anyway.

Reactions: 1

LAF

· #24 · 3 mo ago

Mellow said:
Nice... I like how you have your Denali lights pointed towards them to show them off...

Centerstand shield? Purpose? Thoughts?

Well it really saves the CS and the area the stand takes up. It is like a bash plate of more a sandblast plate. It really saves that whole area and CS from getting pitted and road blasted.

Reactions: 1

LAF

· #25 · 3 mo ago

In 2017 I did a small write up of the "service" I did to the flap and cables. I think if done at each rear tire change it would keep the flap happy.

Flap Clean

Reactions: 1

Mellow

· #26 · 3 mo ago

LAF said:
In 2017 I did a small write up of the "service" I did to the flap and cables. I think if done at each rear tire change it would keep the flap happy.

Flap Clean

Happy Flappy, Happy Life.... lol.. I shouldn't start drinking so early in the morning.. or maybe I should start.

Reactions: 1

Rich_Blue21RTLE

· #27 · 3 mo ago

I am being told by my dealer that the exhaust flap assembly was modified mid 2021 to prevent it sticking. I have seen the diagrams of the modification but to be honest, couldn’t really understand what I was looking at. Unfortunately, the modification is not applied to your existing exhaust, it still requires new header pipes which have been built with the modification. All new bikes should have the modified exhaust. They say from the feedback that it seems to have resolved the problem.

My 21RT has thrown the warning light a couple of times now but has somehow righted itself. This was discussed when my bike went in for a service on Thursday, whereby the dealer confirmed from the download that the flap had stuck a couple of times. But because it was not actually stuck when I presented it to the dealer and the computer showed it was intermittent, they have just cleaned and lubricated it. We will see how long it lasts …..

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Audi403

Discussion Starter · #28 · 3 mo ago

LAF said:
Well if it was me I would put a set of headers on and be done.

I use Akrapovic headers and do not miss the flap at all. It's whole function is noise abatement and nothing more. You can buy a Servo Buddy and that takes care of the dash light when not having that mess on your exhaust.

All of Akrapovic's headers come with the valve now. They claim it's for "improved rideability in lower rpm"

Geekmaster

· #29 · 3 mo ago

What lubricant is recommended for the flap mechanism?

LAF

· #30 · 3 mo ago

Audi403 said:
All of Akrapovic's headers come with the valve now. They claim it's for "improved rideability in lower rpm"

That sucks! EPA or something for sure. I am so happy I have a antique 1200 GS!

I have the exhaust I want and I have a Power Commander 5 with Auto Tune that has a dyno made fuel map. It runs wide band O2 sensors to replace the OEM. I think now they have stopped that on the 1250 and you run a combination of the OEM fuel map and the PC5 map. Not what I would want.

I also have a Service DVD and a Haynes manual.

I hate to admit it but I wanted a R18 and at the prices and incentives I was ready to pull the trigger. Except I would not be able to service it properly. I will never buy something I can not take care of myself. It is a shame BMW has done this. It has and will drive people to other name brand bikes or back to the older antique 1200s that you can get and still be modified a bit.

It is a shame they are locking all the tunning and exhaust options for later bikes. They are leaning them out to make Euro 5 or 6 and you end up with a bike that is lean running and no way to help it out. It makes a difference when they are a bit fatter in the fuel cells especially in the low RPM and TPS settings.

My 2017.5 dyno was 113 [email protected] RPM and 83 Torque @6.46 RPM. It is fat enough on fuel that I have no worries running the dill out of it. And while not 1250 numbers it is fast and quick enough for me.

And it is paid for!

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Audi403

Discussion Starter · #31 · 3 mo ago

LAF said:
That sucks! EPA or something for sure. I am so happy I have a antique 1200 GS!

I have the exhaust I want and I have a Power Commander 5 with Auto Tune that has a dyno made fuel map. It runs wide band O2 sensors to replace the OEM. I think now they have stopped that on the 1250 and you run a combination of the OEM fuel map and the PC5 map. Not what I would want.

I also have a Service DVD and a Haynes manual.

I hate to admit it but I wanted a R18 and at the prices and incentives I was ready to pull the trigger. Except I would not be able to service it properly. I will never buy something I can not take care of myself. It is a shame BMW has done this. It has and will drive people to other name brand bikes or back to the older antique 1200s that you can get and still be modified a bit.

It is a shame they are locking all the tunning and exhaust options for later bikes. They are leaning them out to make Euro 5 or 6 and you end up with a bike that is lean running and no way to help it out. It makes a difference when they are a bit fatter in the fuel cells especially in the low RPM and TPS settings.

My 2017.5 dyno was 113 [email protected] RPM and 83 Torque @6.46 RPM. It is fat enough on fuel that I have no worries running the dill out of it. And while not 1250 numbers it is fast and quick enough for me.

And it is paid for!

I don't believe Power Commander makes anything compatible with the R1250 engine. I just installed Akrapovic headers and slip-on on my 2019 R1250RT. It runs fine but I know it's probably a little on the lean side. I ordered the BT Moto Stage 1 tune. I've heard good reviews from other members on this forum for their flash.

I agree about the service manuals. Ducati has not been producing service manuals either. Atleast since I bought mine back in 2018...

Reactions: 2

LAF

· #32 · 3 mo ago

I guess in 10 years people will be looking for hacks to take the limiters off their electric motorcycle

I do realize not everyone wants a new exhaust or to mess with the stock fuel maps by adding tunes but it has been just about every bike I owned exhaust and fuel mods, and when I had some money, shocks. That went for my cars too except it was wheels and tires and brakes and shocks and tune.

I have a little Honda Accord 4 cylinder 6 spd Coupe that I did a E Tune on. I made 21 pulls and sent the map to Turbo Gixxer to adjust. I would make a run, send the map, load the one sent back and do another pull. I did that 21 times in the matter of a week or so and he adjusted a bunch of stuff but most important when VTEC (read shiftcam) kicked in. It is a 93 octane tune. I can take it off and flash it back if I want but have not in 9 years. I get 25 MPG around town with sane driving, and around 35 on a trip so I am ok with that and feed it 92 or 93 100% of the time. It will burn some gas stoplight to stoplight hard running but like my bike it is all dependent on the right side of my body, and in the car, how fast my left leg can work the clutch, no quick shift there

The ending of exhaust mods we all have seen coming I think. The fuel or tuning also. The addition of that third O2 sensor on the 1250 really knocked that one in the dirt. I know I could not buy a Remus header pipe in CA because CA would not allow the manufacture of them and at that time Remus was based there.

I know nothing of the BT. I would love to see a dyno of before and after on a owner's bike. Can you flash and un flash them? Can they E Tune for you? I would love to have something I can flash and un flash at home or on the road. To turn my bike to stock I have to replace both O2 sensors, plug the injectors back into the stock plugs, and take a TPS wire tap off. I carry what I need to do that with me. It would be nice to just have a flash device like my K Tuner or another one by HonData.

I look forward to your thoughts on the BT and if they can then e-tune to your bike? I paid 300 bucks for my e tune and that is what I paid to have my bike dynoyed to make the PC 5 map. But PA Dyno did my bike twice for me as he had a brand new dyno from DynaTune and wanted them dialed in on the second day to make sure it was correct.

Please let us know how that tune works out for you.

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Audi403

Discussion Starter · #33 · 3 mo ago

LAF said:
I do realize not everyone wants a new exhaust or to mess with the stock fuel maps by adding tunes but it has been just about every bike I owned exhaust and fuel mods, and when I had some money, shocks. That went for my cars too except it was wheels and tires and brakes and shocks and tune.

I have a little Honda Accord 4 cylinder 6 spd Coupe that I did a E Tune on. I made 21 pulls and sent the map to Turbo Gixxer to adjust. I would make a run, send the map, load the one sent back and do another pull. I did that 21 times in the matter of a week or so and he adjusted a bunch of stuff but most important when VTEC (read shiftcam) kicked in. It is a 93 octane tune. I can take it off and flash it back if I want but have not in 9 years. I get 25 MPG around town with sane driving, and around 35 on a trip so I am ok with that and feed it 92 or 93 100% of the time. It will burn some gas stoplight to stoplight hard running but like my bike it is all dependent on the right side of my body, and in the car, how fast my left leg can work the clutch, no quick shift there

The ending of exhaust mods we all have seen coming I think. The fuel or tuning also. The addition of that third O2 sensor on the 1250 really knocked that one in the dirt. I know I could not buy a Remus header pipe in CA because CA would not allow the manufacture of them and at that time Remus was based there.

I know nothing of the BT. I would love to see a dyno of before and after on a owner's bike. Can you flash and un flash them? Can they E Tune for you? I would love to have something I can flash and un flash at home or on the road. To turn my bike to stock I have to replace both O2 sensors, plug the injectors back into the stock plugs, and take a TPS wire tap off. I carry what I need to do that with me. It would be nice to just have a flash device like my K Tuner or another one by HonData.

I look forward to your thoughts on the BT and if they can then e-tune to your bike? I paid 300 bucks for my e tune and that is what I paid to have my bike dynoyed to make the PC 5 map. But PA Dyno did my bike twice for me as he had a brand new dyno from DynaTune and wanted them dialed in on the second day to make sure it was correct.

Please let us know how that tune works out for you.

I do the same, I enjoy tinkering with my vehicles. I had a 2012 Audi S4 for 7 years. It had an intake, exhaust, smaller pulley on the supercharger, stage 2 tune, + a whole bunch of other stuff. It was putting down ~400whp. I haven't had a sports car for a few years now though, just a Toyota Tacoma that isn't worth doing any performance mods to. I've had 6 bikes over the years and they've all had atleast an exhaust on them.

The BT Moto tune comes with a handheld flasher. You can put it back to the stock tune yourself. I haven't asked them about custom tuning or e-tuning. I'm guessing they probably have the ability to do that for an extra charge.

Here's a link to their available products for the R1250s:

BT Moto | 50 State Legal Performance ECU Tuning And Race Parts

BT Moto Brings You High Performance ECU Tuning From Anywhere In The World. Our Engineers Focus On Solutions For Everyday Riders, Weekend Warriors Or Full Blown Track Racers

bt-moto.com

The Stage 1 dyno that they posted showed an increase of 6.2 ft-lbs of torque and 8whp. The Stage 2 dyno shows 11.3 ft-lbs of torque and 12.7whp.

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All the details are on their website so I won't bother copy/pasting it here. I was chatting with another member here who has their tune. He said Stage 1 made a very noticeable difference in smoothness and tractability. He did the Stage 2 with the velocity stacks later on. He said, "it feels quite a bit quicker and is fuelled perfectly. Has more grunt but also pulls a lot harder up top."

I ordered only the Stage 1 for now. I'll let you know if I notice any difference. I've ran the Akra headers and slip-on for about 200km over the last few days. The bike is running well with no check engine lights. Interested to see what sort of difference I can notice from the tune.

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LAF

· #34 · 3 mo ago

Audi403 said:
I do the same, I enjoy tinkering with my vehicles. I had a 2012 Audi S4 for 7 years. It had an intake, exhaust, smaller pulley on the supercharger, stage 2 tune, + a whole bunch of other stuff. It was putting down ~400whp. I haven't had a sports car for a few years now though, just a Toyota Tacoma that isn't worth doing any performance mods to. I've had 6 bikes over the years and they've all had atleast an exhaust on them.

The BT Moto tune comes with a handheld flasher. You can put it back to the stock tune yourself. I haven't asked them about custom tuning or e-tuning. I'm guessing they probably have the ability to do that for an extra charge.

Here's a link to their available products for the R1250s:

BT Moto | 50 State Legal Performance ECU Tuning And Race Parts

BT Moto Brings You High Performance ECU Tuning From Anywhere In The World. Our Engineers Focus On Solutions For Everyday Riders, Weekend Warriors Or Full Blown Track Racers

bt-moto.com

The Stage 1 dyno that they posted showed an increase of 6.2 ft-lbs of torque and 8whp. The Stage 2 dyno shows 11.3 ft-lbs of torque and 12.7whp.
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All the details are on their website so I won't bother copy/pasting it here. I was chatting with another member here who has their tune. He said Stage 1 made a very noticeable difference in smoothness and tractability. He did the Stage 2 with the velocity stacks later on. He said, "it feels quite a bit quicker and is fuelled perfectly. Has more grunt but also pulls a lot harder up top."

I ordered only the Stage 1 for now. I'll let you know if I notice any difference. I've ran the Akra headers and slip-on for about 200km over the last few days. The bike is running well with no check engine lights. Interested to see what sort of difference I can notice from the tune.

Thank you for the info will look at the site in depth.

Yes no matter what headers and exhaust give these bikes a bit of sound. It is not obnoxious and even without the flapper it is only louder on start up and idle, as duh it has no flap, but once under way you can stay pretty close to OEM sound output.

However I find that very boring on two lane country roads here in PA

I have always believed it was a combination of condensation, combustion build up, and heat that is causing the flap issue. I mean anyone who has cleaned butterfly valves on intakes know how crudded up they get, so now we have a exhaust pipe with one in it. I think the pipe and valve get carbon build up, is slows or stops the action, and then condensation just tears up the tiny spindle that butterfly spins on. I hope as a previous poster says it has been fixed on new bikes. My problem is how about all those who have had to buy new headers and now find out it is the same design they had? One has to always remember not every BMW rider is on a Forum.

Just what I think. I also believe it can be "serviced" every rear tire change by cleaning it and using some type of copper or graphite based slur forced into the cup. We should not have to, but we should. I did it to my 15 RT every tire change along with stripping the brake calipers to clean and lube and inspect. Just how I was shown to care for things.

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Audi403

Discussion Starter · #35 · 3 mo ago

LAF said:
I have always believed it was a combination of condensation, combustion build up, and heat that is causing the flap issue. I mean anyone who has cleaned butterfly valves on intakes know how crudded up they get, so now we have a exhaust pipe with one in it. I think the pipe and valve get carbon build up, is slows or stops the action, and then condensation just tears up the tiny spindle that butterfly spins on. I hope as a previous poster says it has been fixed on new bikes. My problem is how about all those who have had to buy new headers and now find out it is the same design they had? One has to always remember not every BMW rider is on a Forum.

Just what I think. I also believe it can be "serviced" every rear tire change by cleaning it and using some type of copper or graphite based slur forced into the cup. We should not have to, but we should. I did it to my 15 RT every tire change along with stripping the brake calipers to clean and lube and inspect. Just how I was shown to care for things.

My original 2019 headers have 22,000km on them and the valve operates completely free. I've never done any cleaning or maintenance on it. Now that I have the Akrapovic headers, I have a new valve. I'm not sure if the Akrapovic valve is known to fail? There's probably not enough people running them for it to be a known issue. If it does fail, I'll be cutting it out and having a piece of straight pipe welded in it's place.

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speedtoys.racing

· #36 · 3 mo ago

The occasionall servicing isnt a bad idea, its just a rough environment, and stopping galling will prevent it just freezing up if you stop it starting. Its just metal on metal, with a spring asking it to unloaded evenly along the shaft over time.

LAF

· #37 · 2 mo ago

Audi403 said:
My original 2019 headers have 22,000km on them and the valve operates completely free. I've never done any cleaning or maintenance on it. Now that I have the Akrapovic headers, I have a new valve. I'm not sure if the Akrapovic valve is known to fail? There's probably not enough people running them for it to be a known issue. If it does fail, I'll be cutting it out and having a piece of straight pipe welded in it's place.

I think with a sharp enough chisel you could just knock it out. It would be what I would try on a stock header before I paid for a new header from BMW.

joeducati

· #38 · 2 mo ago

Barrie said:
My flapper valve is stuck and engine warning light is on. When I opened it up to see if there was any movement on turning on ignition, some times it tries to move and other times it doesn't. According to BMW Motorrad, mine has had two replacements already. Not good if it costs £1500 a time.

I would just unhook the cables and make sure the flapper is wide open and just don't hook up the cables again, just leave the flapper open, it's spring loaded. The exhaust will be a bit louder at idle since the flapper stays wide open, but I didn't mind that on my stock setup.

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