Exhaust Flap Bowden cables R1250RT

[Hors Piste]

Whilst investigating the possible cause of a "check engine light" on the dash - GS911 indicates it's a problem with the exhaust flap/servo system (at only 5700 miles  :'( ) I noticed that at least one of the Bowden cables between the servo and the flap is resting on a small "loop" of metal welded to the top of the cat.  Indeed, the only purpose of this loop appears to be to keep the cables from actually touching the cat itself.  Given the temperatures reached here this strikes me as being a fairly crude way of doing things - so my question is "are they all like that sir?".  If anyone doesn't mind lying on the floor and seeing where their cables lie I'd appreciate further info.

(I note that these cables don't have the "heat shielding" mentioned in the repair manual for the 1200RT - I don't have a 1250 DVD to compare)

Thanks

[MikeS]

Is this what your asking about? Photo from my 1250.[attachimg=1]

[Hors Piste]

Yes - in that photo it looks like one of the cables is actually resting (rubbing?) on the "loop", as is one of mine. In 10000 miles on my previous RS I had no problems with the flap, so never had occasion to look at that area. However, as I say above the repair DVD refers to "heat shielding" on the cables on the 1200, but there is no such shielding on the 1250. I wondered if they had replaced the shielding with the "loop".

Still seems ridiculous that they would make the flap assembly part of the exhaust / catalyst system  >:(

[Casbar]

Yes - in that photo it looks like one of the cables is actually resting (rubbing?) on the "loop", as is one of mine. In 10000 miles on my previous RS I had no problems with the flap, so never had occasion to look at that area. However, as I say above the repair DVD refers to "heat shielding" on the cables on the 1200, but there is no such shielding on the 1250. I wondered if they had replaced the shielding with the "loop".

Still seems ridiculous that they would make the flap assembly part of the exhaust / catalyst system  >:(

Well it was a problem on my 2014 RT, I had two sets of headers. The seizing of the flap has nothing to do with the cables. It is because the flap inside the exhaust seems to seize closed, possibly when the bike has been ridden and then left standing for some time. The spindles do not go into any kind of bearing, just straight into cups. I have just recently freed one on a 2015 RTp, it took around an hour to free, but it has started to squeak again, so freeing off and lubing doesn't seem to be a perm fix. Yet others have had no issues with the flap. Some as a matter of routine grease the spindles in the exhaust with high temp copper grease like permatex, and lube the mechanism. Others do nothing. Whilst I have a warranty, I'm not going to bother to touch it.

[Hors Piste]

Hmm - my flap hasn't seized (no laughter please missus), at least if I take the cover off I can turn it quite easily.  But I do have the yellow engine warning light on the dash.  GS911 says it's the "emissions" system/ flap servo.  Can clear the fault and all is fine for a few runs, then the light comes on again.  Maybe it's the servo itself?  I want to take it to a BMW dealer, not a "BMW plus as many other makes as we can cram into the showroom" dealer - but I can't go anywhere until at least 9th Nov now  :eek:

[Casbar]

Keep us informed of the issue, I have only so far experienced the issue with the 1200s  8)

[Arek]

I have way over 6K miles on mine and didn't noticed any issues at all.
So I'm curious what conditions actually made it worst. I'm riding regardless temp and rain, so can say all weather rider.

[Casbar]

I have way over 6K miles on mine and didn't noticed any issues at all.
So I'm curious what conditions actually made it worst. I'm riding regardless temp and rain, so can say all weather rider.

So do I, my 1250 is ok with 5k at the moment. The one I have just freed on a RTp, is a blood bike, so has done 50k and is in constant use. My 2014 bike that had two sets of headers was also in constant use year round, averaging 10k a year, I bought it used in 2015 with around 2k on the clock, so wasn't used much before i bought it. Had the headers replaced, then 2 years later I had put 18k on it and they needed replacing again. There has been several threads about this, it seems less prevalent in North America, so maybe it is something to do with our climate in Europe and winter riding

[Hors Piste]

I shall update this thread when I have news to report. The bike has been used in all weathers and very seldom for journeys less than about 100 miles. Two things had happened before the yellow dash light came on - I had cleaned the bike and applied ACF50 about a week before, and I had ridden to the dealer (about 8 miles) to look at what they had in the showroom (M&P in Cardiff had just opened the BMW showroom). On leaving the showroom and starting the bike the yellow light came on and stayed on. It had never done this before.
Suspecting a flap fault I plugged in the GS911 when I got home which indicated a fault with the "emissions" system/flap/servo. I removed the silencer and flap cover to have a look inside - I did notice that beneath the heat shield and on the flap spring mechanism there was no sign of ACF50, so it looks as though my application the week before had not found its way under there and hence seems unlikely to be the cause of the issue? I tried moving the flap by hand and it seemed a little "sticky" so I just moved it back and forth a few times and it seemed to free up a bit. I cleared the fault with the GS911 and tried switching the ignition on and off whilst watching the flap - it moved (although I have to admit that I don't know what it's supposed to do at that stage) briefly through an angle of I'd guess about 35-40deg and then returned to the fully open position, but the light did not stay on. So I put everything back together and went for a ride - all appeared to be fine, no lights.
I had a couple of rides after that without problems and then visited the dealer again last Friday. On leaving and starting the bike all seemed well but then I remembered that I wanted to adjust the DRL setting so I stopped the engine and did that. On starting again the yellow light was back...……
So I took the silencer off again, this time removing the Bowden cables (which is when the question arose about the heat shielding) and moving the flap by hand. Without the cables I could of course move it through a greater range, once again it felt a little "sticky" but a few turns back and forth seemed to loosen it up. So everything now back together awaiting another test run.
I'm not wholly convinced by the "weather" theory - as I say, my previous 1200RS did 10,000 miles in essentially the same weather conditions and had no problems with the flap. (and these darn things are fitted on GS's where they presumably get drowned in all sorts of crap...)  Still, we shall see....

[Casbar]

Good write up. GS suffer just as much with the flap as RTs, so it is not just RTs. There is a chap on UKGSER at the moment with a duff flap on a new GSA. The flap should move from fully open to fully closed when you switch the ignition on. It shouldn't feel sticky it should be totally free. If you take the cables off it should spring open from closed easily. From your description I would still say its the flap sticking, offering resistance. I bought some permatec high temp grease, which I lube the spindles inside with a cotton bud. But I did all that on the 2014 I freed up, and it has still started to squeak again. It must cost BMW a fortune in new headers, I would have thought they might have sorted this out by now.

[Hors Piste]

Hmm - mine won't go fully closed if I turn it by hand. I didn't try forcing it because I assumed that it would never fully close as that would be weird to say the least? But if it should close fully as you say then mine is definitely not right. I'm not keen on taking it to the local dealer (they butchered the well nut on the RH side panel when I had the first service done in the summer),even when our current "firebreak" ends. Next nearest would be Lovett in Bristol I guess, if and when I'm allowed to cross the bridge...

I've just read and posted on the UKGSer thread - don't think I'll be queuing up for a 2021 RT until BMW sort this design out  :beee:

[Casbar]

If you take the cables off and the flap will go stop to stop, ie push against the spring all the way and then it springs back to open on its own and with no friction, then it should be ok. When I say fully closed, I mean as close as a piece of metal can against the pipe edges, so as I said, stop to stop. I've no idea why they don't sort this out, they made an update around 2018, but it doesn't seem to have made any difference.If you pm me with your email, I can send you a small vid of the one I freed on a 2015 RTp, can't upload it here. Not that exciting though

[Tiedend]

I have had a 1200LC (3/2017) & now have a 1250LC (3/2019).

My 1200 never had a problem but my 1250 is having new headers in a weeks time after 2nd time the eml came on. It been put down to the flap. I’ve done 10k miles now. Would have been 15k but for this summer’s issues.

It has squeaked a few times in the last 2-3 months on turning the ignition on whereas my 1200 never did.

Shall be keeping an ear out for problems before the warranty runs out.

[Hors Piste]

Thanks for the offer Casbar - I've watched a few you tube videos of them being freed off :))
Yes, mine will not go to the "closed" stop on the mechanism and I haven't tried to force it as it is clearly a warranty job so it'll just have to wait until I can get it done. Wonder if the dealers keep the headers (plus cat of course - the expensive bit) in stock - somehow I doubt it.
Sorry to hear your tale of woe Tiedend

[Tony Fyson]

My 2019 RT1250 engine malfunction light was illuminated on several occasions.  I checked the exhaust flap, wriggled it and the malfunction light went out.
Again the light came on after a few weeks.


The header pipes (including exhaust flap) were replaced under warranty, as they were beginning to rust! - gasp of astonishment!  The problem disappeared.
However, the flap has now started squeaking, when the ignition is switched on.


Any idea what lubricant is best for overcoming the squeak?