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K100-forum.com » Technical, repair and troubleshooting » Kill that dreadful rattling noise (3,700-4,500 RPM)

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Beemer Wheeler

Beemer Wheeler
Gold member
Gold member
No more screechin Kawa 500 Mach 3 two stroke eering noise.

On my RT, it came from the muffler's heat guard plate.
While tapping whith my finger on it, I noticed a little play in the fixation screw(s).
It made the same kind of beer cans rolling down grand Canyon noise it does when cruising at about 100 Km/h = from 3,700 til 4,500 RPM.
The length between the two screws make that plate resonate at that frequency, much like the strings on my Fender (Pearl) Bass.
I squeezed a small piece of corcK between the zort and the heat guard plate, putting the later "under small tension".
Test rode it for 100 Km, the damned squealer has finally shut up.



Last edited by Beemer Wheeler on Sat Aug 17, 2013 8:36 pm; edited 3 times in total


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1986 K 100 RT "K-T" short for "Katie" 120.000 Km
   Kill that dreadful rattling noise (3,700-4,500 RPM) 2cr0y2r  Kill that dreadful rattling noise (3,700-4,500 RPM) 116p8ic
1998 BMW 318i Cabrio
2012 Yamaha YFL 381 (Flute)
2005 Yamaha PSR E-203 (Keyboard Synth).
2012 Yamaha 7 HP outboard engine
"Beemer Wheeler" Certified Brick Aviator since July 2013
Ham radio call sign HA5AH
http://h2fuel.mobi
    

RT

RT
Life time member
Life time member
I went one better and ditched the guard altogether and polished the pipe. No more rattle. Didn't melt the pannier either, which was my worry.


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2011 R1200RT
    

Beemer Wheeler

Beemer Wheeler
Gold member
Gold member
Way to go :  All the way !
A less radical, more "classy" way would be to add a screw or two, by welding some inox nuts on the zort.
How did you identify the source of the noise ? RT


__________________________________________________
1986 K 100 RT "K-T" short for "Katie" 120.000 Km
   Kill that dreadful rattling noise (3,700-4,500 RPM) 2cr0y2r  Kill that dreadful rattling noise (3,700-4,500 RPM) 116p8ic
1998 BMW 318i Cabrio
2012 Yamaha YFL 381 (Flute)
2005 Yamaha PSR E-203 (Keyboard Synth).
2012 Yamaha 7 HP outboard engine
"Beemer Wheeler" Certified Brick Aviator since July 2013
Ham radio call sign HA5AH
http://h2fuel.mobi
    

RT

RT
Life time member
Life time member
I was reasonably unaware of the problem except at idle I could hear a bit. One ride I went on, I think
Col behind me told me he could hear it over everything else on the highway. The cure would've been to reweld the little nuts in but I'm a jubbo with anything like that so off it came.

I'm in the process of cleaning up a spare exhaust I've had for a while and it has all the right bits on it including heat shield so I might be trying it again.
I did put some insulation on the bottom of my LH pannier just in case but it doesn't seem to be a problem if I'm on the open road. The exhausts aren't really a beautiful piece to look at naked. (unlike myself for example).
RT


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2011 R1200RT
    

Rick G

Rick G
admin
admin
The shield became loose on my K100 and it was all you could hear at highway speeds.


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"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

rosskko

rosskko
VIP
VIP
Previous owner decided the best place for the battery breather hose to vent was onto the lovelly chromed heat shield.
Off she came.


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1986 K100RT VIN 0093801K100RT with summer fairing for a northern visitor

Basic/2 6308802K100CJ  05/1988

K1100RS 0194321
    

Ghost who rides

Ghost who rides
Life time member
Life time member
Good idea but maybe the cork will burn out fairly quickly? Fibreglass may be better?


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1986  K 75 C   2nd owner 187,000kms showing .
1987  K100RT  Police repainted, rough and unloved.
    

Beemer Wheeler

Beemer Wheeler
Gold member
Gold member
---> RT it is not because one ore more screws are a bit lose, or unwelded nuts that it resonates.
It is because the screws are too far apart, the length of the plate between anchor points is right on the frequency produced by the engine around 4,000 RPM.
The plate vibrates like a steel drum...
I'm amazed that BMW "bureau d' étude" engineering team didn't fix that.In AC/refrigeration, high pressure (exhaust pipe of compressor are bent like a trombone at different lenghts to create standing wave traps suppressing resonance and making the compressor and system run quieter.
Less vibrations = less stress on the weldings, = less leaks.


Ghost ---> This "corcK" is actually a piece of "Marine Deck" (tm ?) of corck "sawdust" mixed with some (epoxy ?) resin for boat deck.
It didn't burn, but will be replaced with some stove ceramic fiber mesh (asbestos cleaner alternative) later.
It was just a test, I expected it to burn...


RossKo ---> Mine is black and a bit rusted at one place, I will check that breater tube, it might be "standard" feature ?



Last edited by Beemer Wheeler on Sat Aug 17, 2013 8:40 pm; edited 1 time in total


__________________________________________________
1986 K 100 RT "K-T" short for "Katie" 120.000 Km
   Kill that dreadful rattling noise (3,700-4,500 RPM) 2cr0y2r  Kill that dreadful rattling noise (3,700-4,500 RPM) 116p8ic
1998 BMW 318i Cabrio
2012 Yamaha YFL 381 (Flute)
2005 Yamaha PSR E-203 (Keyboard Synth).
2012 Yamaha 7 HP outboard engine
"Beemer Wheeler" Certified Brick Aviator since July 2013
Ham radio call sign HA5AH
http://h2fuel.mobi
    

RT

RT
Life time member
Life time member
Ok so my original solution of putting a bit of rubber thong (flip flop) would have had the same result.
I just thought that without the heat shield I would get a good opportunity to teach the grandkids the meaning of "don't touch the shiny thing". Told you so, get the ice. Hahahahahahahahah. Whoops, lost it again.


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2011 R1200RT
    

Beemer Wheeler

Beemer Wheeler
Gold member
Gold member
RossKo --->  It must be standard, the breather is just above the guard plate...
Must change that so it can ruin the clutch cable instead  Wink


__________________________________________________
1986 K 100 RT "K-T" short for "Katie" 120.000 Km
   Kill that dreadful rattling noise (3,700-4,500 RPM) 2cr0y2r  Kill that dreadful rattling noise (3,700-4,500 RPM) 116p8ic
1998 BMW 318i Cabrio
2012 Yamaha YFL 381 (Flute)
2005 Yamaha PSR E-203 (Keyboard Synth).
2012 Yamaha 7 HP outboard engine
"Beemer Wheeler" Certified Brick Aviator since July 2013
Ham radio call sign HA5AH
http://h2fuel.mobi
    

Beemer Wheeler

Beemer Wheeler
Gold member
Gold member
What was most worrying about that noise was it's unknown (to me) origin, it sounded like a major lose rod event, or at least could mask the sound of mechanical breakdown should it happen.
It was most un nerving when riding a 5 Km long tunnel in Holland under the Schelde Delta in Zeeland Holland.
It's an eery place for a breakdown, I'm taking it again tomorrow without the vibraphone.
This plate is (by BMW design) free to oscillate between two fixing screw distant about 40 cm a bit more than 1'), just like thepieces of wood on a Xylophone.
As a musician, I would like to make a statement:  This sound was out of tune, discordant, unharmonic, and reminds me of the dentist's drill.


__________________________________________________
1986 K 100 RT "K-T" short for "Katie" 120.000 Km
   Kill that dreadful rattling noise (3,700-4,500 RPM) 2cr0y2r  Kill that dreadful rattling noise (3,700-4,500 RPM) 116p8ic
1998 BMW 318i Cabrio
2012 Yamaha YFL 381 (Flute)
2005 Yamaha PSR E-203 (Keyboard Synth).
2012 Yamaha 7 HP outboard engine
"Beemer Wheeler" Certified Brick Aviator since July 2013
Ham radio call sign HA5AH
http://h2fuel.mobi
    

JimK

JimK
Gold member
Gold member
Took the obnoxious shield off the other day too.
Not sure what will do.

Will not polish the system....but that is some seriously incredible work that some of you have done!

Anyway, have decided that I can certainly live with the matt/flack black color that the header/front down tubes of the exhaust have, and would like to have the whole system be the same...sorta matches the frame....and that is ok with me, for now.

Any ideas about how that might be done?
I do have access to various cutting and welding tools if it might be a question of heat alone.

Musing.....

Regards,
Off the wall Jim...Smile


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'89 k100 rs se
    

Beemer Wheeler

Beemer Wheeler
Gold member
Gold member
Jim, I think you can heat the tubes manifold and the zort with a blow torch, and it should darken, or turn to a nice light petrol blue.
Unmount all the parts that would burn like rubber silenblocks, and keep a fire extinguisher handy, there might be some oil residue inside...

The best thing since I suppressed this noise is that I am now sure it's not coming from the engine.
Peace of mind.


__________________________________________________
1986 K 100 RT "K-T" short for "Katie" 120.000 Km
   Kill that dreadful rattling noise (3,700-4,500 RPM) 2cr0y2r  Kill that dreadful rattling noise (3,700-4,500 RPM) 116p8ic
1998 BMW 318i Cabrio
2012 Yamaha YFL 381 (Flute)
2005 Yamaha PSR E-203 (Keyboard Synth).
2012 Yamaha 7 HP outboard engine
"Beemer Wheeler" Certified Brick Aviator since July 2013
Ham radio call sign HA5AH
http://h2fuel.mobi
    

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K100-forum.com » Technical, repair and troubleshooting » Kill that dreadful rattling noise (3,700-4,500 RPM)

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