Flappy valve renovation.

[Delboy777]

Well I reached for my trusty tub of Halford's Copper grease, must be 20 yrs old and says ok to 1150deg. Its convenient, I doubt very very much indeed that this area reaches 1000deg and hey, must be better than nothing. In any case, seems we have no science in this flap failure issue
I know there's people on this site that have clever temperature measuring devices, so before we start a 'what flap lube thread', tell us how hot it is in there.

Use one of them there temp detecting gun thingies.

 

[comberjohn]

The problem is not what kind of grease to use, it's how to get it where it needs to be. As I said earlier, it seems to be the bottom pivot that seizes up. Get it moving and the flap works with no problem.
Here's some pics of what I did today. Not pretty but it's working!
I'll start another post so I can show the rest of the pics.

 

[Fatboydel]

Just chuck it in the bin and be done with it. Took mine out and never looked back.

 

[comberjohn]

So here you can see what I started with and then carefully removed the cover over the pivot.
Once it's removed, you can see the end of the spindle with the composite bush holding it in place. After what Stan had said, I was cautious about removing too much of the bush. You can see some of the shavings I trimmed off using a Stanley knife. Not difficult to cut.
I cut a chamfer in the bush and put some WD40 around it to try and free it up. Wasn't really helping. Using the smallest diameter drill that I have, I drilled four small holes into the bush and tried to get some WD40 in then.
It freed up fairly easily after that.
What I did notice was that the WD40 that was in a small pool around the spindle while I was trying to free it, became black as I turned the spindle.
A build up of carbon from the exhaust over time causing the composite bush to seize?
Using epoxy putty, I sealed up the end of the spindle using a pound coin. Penny was too small!
That's how I've ended up with the blob. It only has to keep the dirt and water out, so we'll see how it goes.
Might be an annual maintenance job but now I know what is in there, it shouldn't be a big deal.
Thanks for the offer of making up a bush and might take you up on it if this doesn't work.

 

[Delboy777]

I've got one that works fine I removed it because I changed my can. If anyone wants it ?

 

[Slipperyeel]

That 'composite bush' looks just like the old exhaust-to-silencer gasket my ST1100 used to use.

They are basically a wire mesh that is graphite filed. I'm guessing they are compressed into shape in a mould and the wire is just to give them some structural integrity until they're fitted. Effectively giving you an all graphite bearing/bush. So the suggestion that the other end of the pivot being the culprit may hold some truth.

I remember well that they are basically fooked once used. Meaning any attempts to rescue them is hopeless.

Maybe the same graphite bushes are used on something else, allowing you to remove it completely and replace. But god knows where you'd start looking?!

 

[dementedmonkey_co_uk]

I've got one that works fine I removed it because I changed my can. If anyone wants it ?

Pm'd I think (tried anyway
Cheers
Ben

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[comberjohn]

And the conclusion. For me anyway.
I've got the valve back together and working ok, but I think I'll leave it on the shelf in the meantime.
Just have no faith in it not seizing in the (very near) future.
But, no more problems with too loud an exhaust over long distance anymore.
Tried my new custom fit, silicone ear plugs today. They're brilliant!
All day comfortable and so quiet. Should have had them years ago. Much better than the foam jobbies.
Highly recommended.

 

[Bendy toy]

I use Moldex Rockets (-30dB)
Reusable silicone, last for weeks, easy to clean with alcohol, all day comfy and don't get disturbed by the helmet.
My bike isn't especially quiet (though not antisocial). At 70, I get more racket from front tyre than exhaust.

 

[dementedmonkey_co_uk]

Got a good used replacement fitted today so have my original to strip sometime if I can be bothered

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[Delboy777]

Got a good used replacement fitted today so have my original to strip sometime if I can be bothered

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[dementedmonkey_co_uk]

Question then... It self tests and on a cold start runs really quietly, on a warm start it self tests and then goes full open at idle, expected behaviour? On the plus side it will be quieter for early morning cold starts

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[AustinW]

I had a spare hour or so today and out of curiosity dug out my flappy valve from the scrap pile and decided to see if I could free it off. The valve would only move with the persuasion of a hammer and I had previously extensively lubed it with everything I had in the garage. The same as others, once I had filed enough of the "cap" away on the non-pulley end of the spindle I found a carbon bush and once I removed enough of that it began to move a bit more easily. I decided to dig out all the carbon bush and filled the well with a mix of releasing oil, wd40 and acf50. After an hour I could move the valve by hand and after 2 more it moves easily and snaps open under spring pressure now.

I just need to find some suitable grease to pack in there and a way of sealing it up and I can put it on the shelf just in case I ever need it or want to put it back on the bike to hide the fault codes. Or, if anyone wants it for some reason......

 

[vRSG60]

I use this : https://www.ebay.co.uk/itm/391745791094


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How do you get the stuff into place? Just coat all the bearing points you can get to on the outside?

 

[oldnfat]

How do you get the stuff into place? Just coat all the bearing points you can get to on the outside?

No, take the silencer off. You will see a groove in the spindle that holds the butterfly valve. This extends into the bushes and in my view is one o the main reasons these things seize. Mine had just about seized, took the silencer off and sprayed anti seize fluid in and left for a few hours. I then keep turning the ignition on and off and helped the butterfly move. After about 20 goes the flap was moving on the full cycle on it's own. Gave another liberal spray and left overnight.

Following day I used a wooden spatula to force in the nickel anti seize grease and repeated the cycles. After about 10 cycles the valve was moving on the full cycle easily....and the squeak that accompanied the start up process had gone. That was 6k miles ago and still working fine.

I will now do this as part of my 6k service and houpefully keep the thing going a little longer.

Cheers

 

[comberjohn]

No, take the silencer off. You will see a groove in the spindle that holds the butterfly valve. This extends into the bushes and in my view is one o the main reasons these things seize. Mine had just about seized, took the silencer off and sprayed anti seize fluid in and left for a few hours. I then keep turning the ignition on and off and helped the butterfly move. After about 20 goes the flap was moving on the full cycle on it's own. Gave another liberal spray and left overnight.

Following day I used a wooden spatula to force in the nickel anti seize grease and repeated the cycles. After about 10 cycles the valve was moving on the full cycle easily....and the squeak that accompanied the start up process had gone. That was 6k miles ago and still working fine.

I will now do this as part of my 6k service and houpefully keep the thing going a little longer.

Cheers

I was taking a look at my flappy valve unit after reading this, still would like to make it work properly, and you mentioned that the groove extends into the bushing.
Nope, it doesn't.
Wanted to believe you, but when I shine a light onto the spindle, you can see the shiny surface where the spindle has been machined to accept the flap.
Think you've just been lucky getting enough lube to flow along the spindle into the bushing.
I'm going to try refitting mine after removing the other end of the housing and trying to getting some lube in there and then sealing it up with epoxy putty. Not pretty, but out of sight.
If I have to do this once a year, I'll be happy enough, so I'll see how it goes.

 

[oldnfat]

I was taking a look at my flappy valve unit after reading this, still would like to make it work properly, and you mentioned that the groove extends into the bushing.
Nope, it doesn't.
Wanted to believe you, but when I shine a light onto the spindle, you can see the shiny surface where the spindle has been machined to accept the flap.
Think you've just been lucky getting enough lube to flow along the spindle into the bushing.
I'm going to try refitting mine after removing the other end of the housing and trying to getting some lube in there and then sealing it up with epoxy putty. Not pretty, but out of sight.
If I have to do this once a year, I'll be happy enough, so I'll see how it goes.

Well, I took the silencer off today and all I can say is that on my valve the groove definitely goes a little way into the lower bush....I know this is the case as I tested it with some brazing wire.....albeit only about 2-3mm. Although on the upper bush you are correct, the groove doesn't extend into the bush. Maybe just manufacturing tolerance differences...who knows. But mine has stopped squeaking and goes through the full cycle.

Went through the same process today and hopefully will hold out a little longer.

 

[NZRalphy]

Just take the valve and motor of and put them in the trash. Fit a SS tube dia63mm x 70mm.

It is a bulshit valve made by a wanker in a shed, and BMW fitted it cos they were told to.