Exhaust valve seized

General discussion of the BMW R1200RT/R1250RT
BobM
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Re: Exhaust valve seized

Post by BobM »

Thanks again fellas for all the info. Yep, warranty has expired so, as it`s running fine at the mo I`ll just leave it, but I think I will try the spray mentioned. As I`ve never had any issues with it, and it is a great bike and fully loaded, I don`t really want to part with it, but I guess I should consider that at some point. Thanks again. 
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aweight
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Re: Exhaust valve seized

Post by aweight »

I have a 2015 RT and it's flap had also seized open, I did the following and it has been fine ever since;


Remove exhaust silencer
Remove Valve cover
Disconnect cables
Use grips to rotate the flap through full movement whilst using WD40 or similar to free up (put a cloth in the exhaust past the flap to stop lubricant soaking into catalytic converter)
Spray spring mechanism and use paintbrush to remove dirt build up
Attach cables
Check operation, flap should move through approx 85 degrees when rev'd

Reassemble cover, apply plenty of WD40 before
Remove cloth
Reassemble silencer
Ride

I did this 10,000 miles ago and checked it recently, all good - dealer quote was £1250+VAT
R1200RT LE San Marino Blue
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Beagle
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Re: Exhaust valve seized

Post by Beagle »

Thanks aweight, wouldnt have thought of rag to protect cat from overspray. Surprised just wd40 has lasted so long with the heat unless it initially dissolved and cleared some carbon.
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David.
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Re: Exhaust valve seized

Post by David. »

Plusgas, http://www.plusgas.co.uk/about-plusgas/ claims,

"It breaks the grip of rust, scale, carbon, paint and gum," thought the carbon bit might be appropriate for the exhaust system.

After freeing off the seized valve, what high temperature lubricant do folks use/recommend to maintain movement.
Last edited by David. on Tue Apr 14, 2020 6:54 pm, edited 1 time in total.
BobM
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Re: Exhaust valve seized

Post by BobM »

Thanks for that info aweight, I will definitely try that. Well I won`t, but I know a guy who will. Cheers.
simbo
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Re: Exhaust valve seized

Post by simbo »

David. wrote: Plusgas, http://www.plusgas.co.uk/about-plusgas/ claims,

"It breaks the grip of rust, scale, carbon, paint and gum," thought the carbon bit might be appropriate for the exhaust system.

After freeing off the seized valve, what high temperature lubricant do folks use/recommend to maintain movement.

Graphite lubricant might be a good option.
The GS 'is' the better bike :-)
hammo
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Re: Exhaust valve seized

Post by hammo »

My 2018 RTLE is now nearly two years old is there any specific symptom to look for which will indicate the exhaust flap is not working correctly ? Cheers .
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Beagle
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Re: Exhaust valve seized

Post by Beagle »

The exhaust can get over 1100 degrees c you need a lubricant to survive this temp. Anything else just gets burnt off and adds to the carbon.


Copied,


Combustion exhaust gas temperatures can be in excess of 1000 degrees C, but are typically about 800 degrees C. Heat it is dissipated as it goes back through the exhaust pipes, but not by all that much. The cans will usually be hot enough to burn you too, but should be at a lower temperature than the rest of it.
Last edited by Beagle on Wed Apr 15, 2020 10:55 am, edited 1 time in total.
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David.
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Re: Exhaust valve seized

Post by David. »

The heat is on now, any advance on 1100 degC, how about Ferroslip https://www.molyslip.co.uk/products/ant ... ferroslip/ good for 1400 degC.
Last edited by David. on Wed Apr 15, 2020 11:45 am, edited 1 time in total.
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David.
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Re: Exhaust valve seized

Post by David. »

Found this posted on UKGSER.

This is the EFCV from a Camhead, I imaging on the Wethead, the construction is similar if not the same.

Image
It's a carbon composite bush. No lubrication involved. Supposed to self lube. Until it doesn't.

Image
You won't get anything in there to free it up unless you get out the angle grinder as I did.
Even then, I had to drill holes in the bush to get some lube in.
The pully end doesn't seem to cause any problems.
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David.
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Re: Exhaust valve seized

Post by David. »

hammo wrote:My 2018 RTLE is now nearly two years old is there any specific symptom to look for which will indicate the exhaust flap is not working correctly?
Remove the plastic pulley cover, when switching the ignition on (without starting),  the valve should cycle through 90 deg. from full open to closed & back again.

Alternatively, remove the silencer and have a look at the flap. If you want to annoy the neighbours fire the bike up like this one.
https://www.youtube.com/watch?v=_ZPfnLnmRg8
Last edited by David. on Wed Apr 15, 2020 12:18 pm, edited 1 time in total.
hammo
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Re: Exhaust valve seized

Post by hammo »

Many thanks i will investigate that .!!!!! Bloody typical eh fantastic weather but we are in lock down !!!!!
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David.
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Re: Exhaust valve seized

Post by David. »

I wonder if the orientation of the spindle/flap has any bearing on the number of failures.

On a Camhead, the spindle/flap is horizontal, whereas, on a Wethead, the spindle/flap is vertical. Could the latter be a point for condensation formed on start up to collect.
The carbon bush at the bottom seems to give the problems with seizing, rather than the pulley at the top.

What was re-designed from 2017 onwards.
Last edited by David. on Thu Apr 16, 2020 9:32 am, edited 1 time in total.
Casbar
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Re: Exhaust valve seized

Post by Casbar »

David. wrote: I wonder if the orientation of the spindle/flap has any bearing on the number of failures.

On a Camhead, the spindle/flap is horizontal, whereas, on a Wethead, the spindle/flap is vertical. Could the latter be a point for condensation formed on start up to collect.
The carbon bush at the bottom seems to give the problems with seizing, rather than the pulley at the top.

What was re-designed from 2017 onwards.

Not a lot was redesigned, there is a slightly larger bulge on the bottom where the spindle is, so guess they attempted to do something with the bushes. I had the new upgrade fitted, it was still squeaking just under 2 years from fitting and others with the later exhaust have had failures.
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David.
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Re: Exhaust valve seized

Post by David. »

Akrapovic manufacture exhaust headers for the 1250, https://www.akrapovic.com/en/moto/produ ... earId=5778

Options are available in Stainless Steel or Titanium. In both cases, they have an exhaust valve, with or without a catalytic converter.

Image

Image

Interesting that the exhaust valve has been retained in all cases.
I wonder if they have had to do this to have them approved for use by BMW.
"Featuring exhaust valve for improved rideability in lower rpm."

Check out the installation instructions to see photos of the different Akrapovic v's BMW exhaust valve.
https://d1sfhav1wboke3.cloudfront.net/I ... a7ee92.pdf
Last edited by David. on Thu Apr 16, 2020 3:00 pm, edited 1 time in total.
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