Vibrations FAQ
compiled & edited by Kristian #562
Please read the Disclaimer before attempting any work in this FAQ.

Picking up Bad Vibes - What can come loose or break?
Steve Johnson #F6501

See What can I check for Sources of Vibration, below

Feedback:

Body Work
by Claude #312
11/28/99

Some of the bolts that hold the front body work on the F650 thread into clips which are known as tinnerman clips (there are other names too but that is sort of generic). These are made of sheet metal and aren't really made to stand up to vibration. You can't use Loctite on them either.

My Bike seems to Vibrate an awful lot. What can I do. ?

Compiled by Kristian #562
15/10/01

 

There a number of sources of vibration on the F650, and if you've been through the list below and it STILL feels rough, then I'm sorry I can't help you any further. Perhaps you just swapped from a very smooth 4 cylinder to the F. Hey it IS a SINGLE, after all and while this is one of the smoothest Big Singles out there, it still vibrates a bit.

 

This FAQ Deals with Vibrations that appear to come through the bike, not your vibrating head , which may be from either too much beer or more likely from Buffeting, caused by Wind Turbulence. If you're looking for information on Buffeting, which is another animal altogether, you need to go the Buffeting FAQ. If you are looking for the source of Strange Noises, see the Strange Noises FAQ.

 

Here's a list of known and suspected sources of vibration or possible solutions to reduce your vibrations. They are in no particular order and while its not an exhaustive list,  these are the most common sources and hopefully will help you quickly identify your problem.

1. Bar-End Weights.

See also Aftermarket Handlebars FAQ for Details of Aftermarket Bars
 

Some of our bikes seem to have come without these or at least, someone maybe forgot to put them back on when they installed heated grips or the Acerbis type of Hand Guards, which are fixed to the end of the handlebar, as opposed to the BMW hand guards, which are fixed a the pivot of the Clutch or Brake. The Bar End Weights sit at the end of your handlebars and dampen the engine and road vibrations. They are plastic coated steel, quite heavy and they can and do rust, if your bike is left outside. If you don't have them, put them on, you'll notice a big difference. Some say they were left off the ST, but I have yet to verify this.

 

The weights are needed if you plan to install the BMW handguards. If you don't have heated grips, the weight P/N is 32 71 7 658 947. Be sure to specify heated vs. non-heated as it was a point of confusion at the local dealers here. Make sure you get the bolts as well. I think the weights and bolts were close to $30. By the way, the weights make a major difference in vibration reduction. Kristian, Newark.

 

2.   Engine Mounting Bolts.

 

These often vibrate loose with Driving or Engine vibrations and can contribute to a lot of Vibration through to the handlebars. These are Large Bolts with primarily Nyloc Nuts that fix the Engine to the Frame. Some are very hard to get to. You will need a 17mm socket for the Nut and an 8mm Allen key Socket to hold the Bolt. To get to the UPPERMOST bolt behind the Engine you will need to Remove the Tank. The Nyloc Nut types are mainly at the front of the Engine. They are located here: Uppermost Front, Next one Down (Easy to miss as behind Exhaust), Bolts 3 and 4, Lower Rear (Smaller), Upper Rear. (Just in Front of Carbs).

 

For the Classic, no-one can actually find the EXACT Torques. Some folks have used 50Nm with no Problems. The Classic Manual says Front and Rear Footrest Bolts and the Centrestand Bolts all get 50Nm. If the GS CD says 41Nm, then 41Nm-50Nm has to be about right.

 

For the F650 Classic (5#)

 

Engine/Crankcase to Main Frame at (Lower, Rear)------ 41-50 Nm (Bolt 10, R)
Cylinder Head to Frame (Top, Rear) ---------------------------- 41-50 Nm (Bolt 14, R)

Engine/Cylinder Head to Main Frame at Top (Front)-----41-50 Nm (Bolt 3, L)
Engine Shell to Engine (Front)------------------------------------- 41-50 Nm
(Bolt 6 & 7, L)
(Note: Bolt 7 = Bolt 8 in the Upper & Lower Pics of the Frames shown in the LEFT jpg). The lower pic is just a bolted rather than welded lower truss)

(L= Right Picture), (R= Right Picture)

From the F650GS Repair Manual CD:
Engine/Crankcase to Main Frame at rear ------------------------------ 41 Nm
Cylinder Head to Frame -------------------------------------------------------- 41 Nm
Engine/Cylinder Head to Main Frame at Top ------------------------ 41 Nm
Engine Shell to Engine --------------------------------------------------------- 41 Nm
Engine Shell to Bracing Tube ------------------------------------------------ 21 Nm (Bolt 2, L)

Bottom Truss to Frame ----------------------------------------------------------- 21 Nm (Bolt 1, L)

Centre Stand to Frame (GS Only) ------------------------------------------ 41 Nm

 

Cylinder Head to Frame, Adjusting Sleeve ---- Zero Play, max 5 Nm
Cylinder Head to Frame, Locknut ---------------------------------------- 100 Nm

 

Classic:

            L                          R                                                                         

          

GS/Dakar:     

            L                          R

                                                                

For the Classic, the bolt at the top, above the carbs is the same as the two bolts in the front that hold the loop is the same as the bolt at the lower front of the motor is the same as the bolts at the rear of the loop. They're all the same, 17mm nut and 8mm Allen.

Did you tighten the TOP engine mount (Rear of Engine)? You'll need to remove the gas tank. Tighten both the bracket that goes to the frame and the bolt that goes through it. On a Classic, the rear bolt of the gas tank goes into a bracket. On the other side of that bracket is another bracket. That other bracket has a hole in it. A bolt goes through the HEAD and through that hole. That is the TOP engine mount bolt. The reason I say to check the TOP one is that the others are all really simple for the dealer to get at, no disassembly required. A lazy tech will tighten the other four or five and call it done. The TOP one has been the culprit for several folks. Might not hurt to get a new Nyloc nut for that bolt if you find that yours is loose. Flash #412

 

3.   Gel Grips or Soft Rubber Hand Grips.

See the Hot Grips Installation FAQ

 

These are self explanatory, but Richard 230 swears by them. Easy to install, can be better than just Hard Rubber. Just take off the Bar End Weight (one Allen Key Bolt in your toolkit) slide off the old Grip, (note the inside end of the Throttle Grip sits OVER a bit of plastic that actually works the throttle cable) and slide on the new one.

 

4.   Exhaust Mounting.

See the Exhaust FAQ or Exhaust Modifications GS

 

Some Staintune and Remus Exhaust Mounting Welds have been know to Crack. The Staintune is lighter than the Stock Muffler, so perhaps that is where the Vibration comes from. If it is the latter, there is no solution for this, unless you want to replace your stock muffler.  Sean #1015 Ottawa Canada - 25-Jul-02

5.   Tyres & Rims
See Tire Opinions FAQ & the Faq-Tires

6.    Aftermarket Bike Mods

See the GS Aftermarket Frame Accessories FAQ
 

When you changed to the Touratech foot pegs, you eliminated the rubber isolation that came with the stock pegs (assuming you have a GS), as I'm not sure what the Classic F had for stock pegs. Someone else mentioned the change in vibration after the conversion, just a few days ago on here. RDW

 

7.    Oil Level

See the Oil Change FAQ or the GS Oil Change FAQ

 

I have had that problem and found that I was low on oil. The bike smoothed out with proper level added. Tully, NYC, #1076

 

8.   Top Box.

See Aftermarket Luggage FAQ and the Aftermarket Luggage FAQ GS

 

Cause N1 : There is too much movement possible between the Rack and the Topcase

Solution : Place a Thin Rubber Mat between the rack and the bottom of the Topcase. Here's another look.

 

Cause N2 : The Key Lock is Vibrating

Solution : Graphite (Grease) inside the Key Lock

 

Cause N3 : Things inside the top case vibrate against the Top-Case Walls

Solution : Rubber Mat against the walls, Foam ...

 

Cause N4 : The thin cover of the rack is vibrating against the rack itself (there is vibration even if the top case is not set on the rack)

Solution : Remove the Thin cover or Inset Foam

 

Cause N5 : You have a Rattlesnake on the Saddle !

Solution: Put it in the Topcase !

 

Here's a few comments and suggestions, gleaned (over time) from the Message Board about Top-Box Vibrations, which may help you :

9.   Anti-Vibration Gloves (Mason #631)

 

http://www.locatorsandsupplies.com/Vendors/Occunomix/antivibgloves.htm

 

10.   Bar-Snake (DavidHPark #711)

See the Aftermarket Handlebars FAQ for Details of Aftermarket Bars

 

To get rid of vibrations use the Barsnake.

11. If you have a GS, and Surging/Stalling Problems
See Custom Fixes for S & S

A few riders have noticed that either using a Power Box (Fuel Nanny) or updated ECU software also reduced vibrations.

12. Bumpy Ride
See the Wheels FAQ

13. Plug Leads and Caps
See the Plug Caps & Coils FAQ

14. Check your Suspension Spring Preload
See the Suspension Tuning FAQ

Problem: (Not so) Good Vibrations. I own a 1994 F650 Funduro with 17,000 miles on the clock, full service history, recent service. Over the last 6 weeks it has developed distinct engine (?) vibrations from about 4,000 rpm upwards. The bike is restricted (don't know about outside Europe, but here bikes can be restricted to 34bhp according to the kind of license the rider has). It has never vibrated like this, I was able to push it up to just under 80mph at ca. 4,700 rpm, when the restriction kit stops any more fuel going into the carbs. The BMW dealer I use say that there is slightly more vibration than normal but can't find anything (e.g. checked the engine bolts). It's now so bad that doing 70mph on the motorway feels like the engine might be blowing to pieces. No need to say, 3rd and 4th at the same rpm similar feeling. Any ideas anyone, please!!!!! Martin, F650 Funduro (1994, the original), Forest of Dean, England.

Solution: I think I've found the solution IT'S THE SPRINGLOAD. I tightened it several weeks ago and completely forgot about the connection. Lowered it last night and went out for a test ride. Seems to have improved considerably.

15: Engine Guard Bolts
See the Aftermarket Engine Protection FAQ or the GS Aftermarket Frame Accessories FAQ

16: Gas Tank Mounting Plate
See Gas Tank Removal-Replacement

Problem: Bad Vibration between 4500-5500 RPM I have a 97 FT650ST with 25,000 miles. I have developed a bad vibration between 4500-5500 RPM. When I shift and the RPM's drop the vibration kicks in. I'm also experiencing a coolant leak from the left side of the motor by the water pump. I don't think they are related but want to put as much info out there to find out.

Solution: I have stripped the bike down. One of the bolts that mount the tank plate had sheered off. The tank mount plate was loose. Thanks for the help.  PeterG. '97 FT650ST.

17: Countershaft Nut
See Chain Sprockets FAQ

Mine developed vibration when the countershaft sprocket nut came loose. It was still held in place by the locking washer but it was loose enough to turn a little with my hand. Will in CA.

What Parts can I safety wire to make sure they don't come loose?
Steve #001
8/24/99

If you ride your F650 off the beaten path very much, you may have encountered loose or missing parts. My latest adventure can be called The shift lever that wasn't there. After 4000 mules to New York and (almost) back to San Antonio, I pulled out to pass (and downshift) and viola! My left foot was flapping air!

The immediate solution was to find somebody with a pair of ViseGrips. Actually, that's not difficult in Central Texas, even on a Sunday afternoon. After I got home - in a driving rain, by the way - I contacted the dealer who contacted BMW about warranty. Shift levers that fall off are not a warranty item.

Since I was not about to pay another $47 for a second replacement, I found another Allen head bolt, only slightly longer than the original, put the thing in a drill press, and drilled! See photo #1. A bit of wire from my old Ford Repair Kit, and viola! No more missing shift lever. See photo #2. Blue Loctite is also a great friend. Check everything before you ride. BTW, I think BMW is really low for not covering the missing lever. It just fell off!

Kristian #562

Have a look at the Sump Plug FAQ for why you should tie-wire the Sump Plug.