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#996276 - 09/06/17 08:09 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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MontanaBud Offline
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I just revved the bike in neutral to 4k to 5k rpms, and there is considerable vibration all over including at the handlebars.

I do run the revs up to that range when riding up to highway speeds, but I don't think I can sense the vibration because the bike is normally full of vibrations in those gears. Only when I hit 6th does the bike (normally) smooth out.

Oil level is at the center of the sight glass.

What about the possibility that the stick coils are failing (already)? Spark is not an issue at those rpms?

#996278 - 09/06/17 08:21 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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dirtrider Offline
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Originally Posted By: MontanaBud
I just revved the bike in neutral to 4k to 5k rpms, and there is considerable vibration all over including at the handlebars.

I do run the revs up to that range when riding up to highway speeds, but I don't think I can sense the vibration because the bike is normally full of vibrations in those gears. Only when I hit 6th does the bike (normally) smooth out.

Oil level is at the center of the sight glass.

What about the possibility that the stick coils are failing (already)? Spark is not an issue at those rpms?


Afternoon MontanaBud

Your 4-5K buzz isn't stick coils, TB balance, vacuum leaks-- At 4-5K under road load it is MECHANICAL.

If you have a bad coil, TB balance issue, or other engine fueling/sparking issue it will be twice as bad at 2K as it is at 4-5K so if you are somewhat clean at 2K the it (IS) MECHANICAL.

I see that you have had this issue for about 60,000 miles & over 8 years now so it obviously isn't something new or just cropped up___ http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=637877&page=1

You might just have a bike where all the original balance tolerances were built at the outer ends of spec.

My guess is that given the length of time that the problem has been with you, & the fact that the engine hasn't self destructed yet, that your problem is a combination of normal boxer buzz coupled with an out of balance crankshaft or poorly balanced clutch assembly. Or possibly a set of pistons that are not properly matched at original assembly. (ie, something mechanical anyhow)


D.R. ___
Sent from my rotory dial wall phone!
#996279 - 09/06/17 08:27 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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MontanaBud Offline
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I have had a similar issue in the past, but it was finally resolved. This is new.

#996281 - 09/06/17 08:32 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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dirtrider Offline
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Originally Posted By: MontanaBud
I have had a similar issue in the past, but it was finally resolved. This is new.


Afternoon MontanaBud

What resolved it last time?


D.R. ___
Sent from my rotory dial wall phone!
#996282 - 09/06/17 08:38 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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MontanaBud Offline
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A misaligned footplate, caused by yours truly, after it was removed for.... what was I doing. Anyway, I tweeked it off balance and caused the opposite side footplate to touch the transmission.

I have checked for that same thing this time, but I see no contact, nor do I know how that could have suddenly cropped up when nothing was done other than a tire change.

#996283 - 09/06/17 08:53 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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dirtrider Offline
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Originally Posted By: MontanaBud
A misaligned footplate, caused by yours truly, after it was removed for.... what was I doing. Anyway, I tweeked it off balance and caused the opposite side footplate to touch the transmission.

I have checked for that same thing this time, but I see no contact, nor do I know how that could have suddenly cropped up when nothing was done other than a tire change.


Evening MontanaBud

If you ONLY did a tire change & your present problem cropped up right after the tire change then it should be easy to find.

Go back over every bolt that you removed or moved during the tire change, look for anything moved or bent by whatever you used to hold the bike up. Look for the exhaust system to be back EXACTLY where it was before the tire change.

If you are definitely getting a buzz (not a shake or vibration) then whatever is causing it is spinning at least two to three times wheel speed. So that is engine, trans, or input side of final drive.

It could be just a normal boxer buzz that is amplified or transmitted by something touching the active drive train that wasn't touching before the tire change.


D.R. ___
Sent from my rotory dial wall phone!
#996313 - 09/07/17 02:55 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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Mark C Online
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norcal
I had this happen once and found the driveshaft needed replacing because of a loose (worn)joint.
Felt it most on highway deceleration.94 R1100RS @ 77k

#996337 - 09/07/17 10:02 PM Re: Help - High Frequency Vibration [Re: dirtrider]  
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MontanaBud Offline
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Originally Posted By: dirtrider
Evening MontanaBud

If you are definitely getting a buzz (not a shake or vibration) then whatever is causing it is spinning at least two to three times wheel speed. So that is engine, trans, or input side of final drive.


As DR and Marc C have suggested, maybe there is a problem with the input side of the final drive? I did replace the drive shaft two years and 15K miles ago. Four years and 48K miles ago, the dealership installed a used final drive unit that had 23K miles on it, but installed a new crown bearing.

Someone down the road suggested a possible pinion bearing going bad. Would it be worth pulling the FD, and if so, what do I look for?

#996340 - 09/07/17 10:43 PM Re: Help - High Frequency Vibration [Re: MontanaBud]  
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TheOtherLee Offline
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Wilsonville, Oregon, USA
Bud -

Have you considered oil analysis? Not guaranteed to show anything but if it does, you know what to persue.


Channeling farfegnugen since 2011.
#996348 - 09/07/17 11:53 PM Re: Help - High Frequency Vibration [Re: TheOtherLee]  
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MontanaBud Offline
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Originally Posted By: TheOtherLee
Bud -

Have you considered oil analysis? Not guaranteed to show anything but if it does, you know what to persue.


Analysis of the FD oil? Or engine oil? I've not considered it, but will. Unfortunately, I just changed those fluids, so will need to give it some more miles.

What could such analysis tell me?

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