Clutch Carrier balancing....

[R65Singh]

I came across this thread while searching for some information about vibration/buzz in my bike and thought to put it out here.  
http://www.bmwmoa.org/forum/showthread.php?t=34882
I remember my clutch components had various paint marks on them and i just put it back the way it came out.  Now I am wondering if PO had put it wrong or it is out of balance.  Any easier ways to balance that stuff?  My carbs are well synchronized and bike runs well....I am still looking for that smoothness for which these bikes are known for.    

[tvrla]

I've forgotten how I attached the cord, but suspend the components from a cord and position them till the assembly hangs fairly level.

[montmil]

Is the vibration issue throughout the engine's operational range or in a specific rpm area?

Monte

[R65Singh]

I've forgotten how I attached the cord, but suspend the components from a cord and position them till the assembly hangs fairly level.

I was thinking about getting it done on a tires balancing machine...if someone is willing to do it.  I think suspending the parts from a threaded cone might work, but not sure what cone can be used.

Monte the vibration is not too bad but is there almost at all rpms, it is sort of an annoying buzz that u feel in the handle bars.

[montmil]

... the vibration is not too bad but is there almost at all rpms, it is sort of an annoying buzz that u feel in the handle bars.

This may not be your exact issue but, if you read the motorcycle publications as I do, you'll note how many current manufacturers are using some sort of bar-end weight in the handlebars to quell vibration and tingling hands.

Do you still have the OEM handlebars? Often, something as simple as a change of handlebars can create a harmonic vibration. Bar end mirrors might do the same thing on a particular bike.

Perhaps try fitting bar end weights and see if that doesn't calm the vibes for you.  My [smiley=2cents.gif]

Monte

[Barry]

If the vibration is throughout the rev range then that isn't right at all and I would be looking for a cure at source if possible. If the carbs are already balanced how about ignition timing which can have a some effect on smoothness also have you checked the engine mounting nuts are torqued up.

If it does come down to the clutch carrier you could run the engine with the gearbox off and experiment with it in different  positions.

[tvrla]

Pull in the clutch at speed (coast) and see if it's still there. It could be tire balance. Lose a wheel weight?

Normally these things don't vibrate all the time - an unbalanced wheel will vibrate at certain speeds and feel fine otherwise.

I've heard of driveshaft u joint mounting bolts coming loose and causing vibration.

[R65Singh]

Thanks for your suggestions guys.  I will list here what i did to the bike within the last month
Replaced rear main seal
Replaced Oil pump seal
Lubed spines
Replaced older style cam chain tensioner to the new style
New Piston rings, Head gaskets, Push rod rubbers, cylinder base gaskets etc.
New spark plugs and wires.

I reset the timing, balanced the carbs, the bike runs fine...although can't ride it at the moment  coz of the weather here.

Monte, I had the handlebars replaced from my suzuki with built in weights and yes i have bar end mirrors.  Suzuki handlebars are more wider and height wise in between European and American styles.  
 
For some odd reason I still think my whole clutch carrier and related components might be out of balance since I could not see any factory paint marks on those parts, the people talk about.  The vibration I am talking about was there before I did the repairs and still about the same, It is not that bad but not as smooth as some bmw owners talk about.  May be I am skinning the hair here.

After reading that thread at BMWOA I started suspecting the clutch carrier.  Some were even talking about weighing connecting rods and pistons with pins to make sure they weight the same on both sides....not sure how far we can go on this, but would love to do some more experimenting with the bike to see how smooth I can get it to run....still not as smooth as my suzuki 400e.

[Barry]

My experience of bar end weights is that any old weight might not work as well as you might think and certainly not as well as factory designed and tested items.

Talking of smooth Suzuki's many years back I had a GN400 single for 14 years from new which was remarkably smooth given it's simple no balancer shaft engine. I didn't like the high wide bars and changed them for low narrow ones.

The original Suzuki bars had steel weights that were a little smaller in diameter than the handlebar welded into the end of the bars so that the inner end of the weight was free to vibrate inside the handlebar.

There was a significant increase in perceived vibration with the new low bars fitted and no matter what I did in the way of  bar end weights I couldn't  make it anything like as smooth as with the stock bar. I concluded that there is more science than meets the eye to designing efficient bar end weights including possibly the shape and width of the bars.

[tvrla]

These bikes aren't perfectly smooth. Also, the newer style clutch system doesn't have much weight to it, and may not be contributing much to the vibration, if at all. It doesn't hurt to balance everything though.

[Dave 2]

When I got my clutch apart the Clymer manuel cautioned to make your own marks before disassembly. I was glad I did this because the original painted marks on the two plates did not make sense to me. I'm fairly certain that I am the first person since the factory build to take it apart. I thought it was interesting to see the number of holes that were drilled into the plates to balance them. D2

[Mike V]

This is more a question than a statement guys, but isn't the clutch carrier on the bikes with the lightened clutch assembly a very low possibility for vibration?  Seems like things would have to be seriously out of balance to generate a state of vibration to me.  There just doesn't seem to be enough mass at the flywheel diameter to shake things up.  I've been wrong before.  Just my opinion.

I would look at the obvious first; engine mounts and torque, cracked frame, general tune and synch of carbs. That is "if" the vibration is consistant with engine operation and not wheel travel.  U-joints?  Driveshaft connection and condition of flange bolts?  Maybe a compression test would be interesting to see how things are pumping.

As spokes stated; these engines are not silky smooth or even as smooth as their larger siblings, especially around 4600 to 5200 rpm. But relatively smooth when things are right, even though their design is "oversquare".

[azcycle]

I couldn't see any balance marks on mine when I pulled them apart, and just put it all back together without worrying about it. I haven't noticed any sort of additional buzziness or vibration (more than normal!)

[R65Singh]

Mike...even though the clutch carrier in 1980plus bikes is lightened but when all the components like pressure plates, spring plate etc, are bolted together and rotate at high speed, even slightest offset of even less than 10 gm will cause some contribution to the vibration.  I think the weight of the all the parts together, is at least 4-5 pounds easy although I did not weigh them personally but they are not light.
Here is what I came up to do the balancing the homemade way.  It worked well for me and I had to fiddle around with various combination of the parts to find the best balance i could achieve.  
There are white paint marks on all the parts even on the round spring plate, and some parts had double white marks which added to the confusion.  I believe they balanced all the parts individually at factory and those white marks are for the "Fine balance".
 I am in the process of putting things back together and will keep you guys posted of the outcome.  Here is the picture of the setup that i used.

[Mike V]

I can remember when I disassembled my clutch pack the paint marks that I "could" locate did not line up either.  I also seem to remember reading somewhere (maybe Snowbum's site) the paint marks may be staggered in some relationship from the factory.  Or could it be my imagination? I was careful to reassemble the components in the same order and reference that they were found since I'm 99% sure I was the first one into my 650.

I'm quite amazed at how smooth the R65 is running, especially after I resolved the carburetor issues.  except at that pesky 4600 to 5200 rpm range.

Interested to hear how this all pans out.  Keep us informed ...

-Mike V.