Buzzing mirror

I recently purchased a one owner 92 R 100 RT with 48,000 miles on. It was serviced by my local BMW dealer and runs great. Although it does not involve the drive and suspension system I do have one agrivating problem. The right mirror vibrates to the point that it is usless. I have taken the mirror and mount off the fairing and reattached it. I have centered the lower brace on the upper fairing and tightened and checked the attachment hardware on top of the fairing, all to no avail. Tightening the lower brace did stabilized it somewhat but I still can not recgonize a car at 100 yards in the mirror. The left mirror is totally stable. It feels that the entire right side of the fairing is shaking..The glass is not loose in the mirror housing. Although worse below 3500 rpm, the mirror still vibrates all the way to redline.

Has anyone else experienced this and what did you do about it?

All feedback is welcome. Thanks in advance.

TexasTiger

Texas Tiger: I have the same problem on my '86 R80RT. Left mirror is reasonably good, right mirror is a blurr. I don't know if it's a function of the way the boxers "torque" or what, but I haven't found a cure either.

Hawk
VP BMWMOA

Don't know if this will help - but try a valve reset and a carb sync. (and, if you can get one of the new Twinmax devices - is easier than other ways to sync carbs).
Doing the set & sync used to help my 82 RRS, anyway.....

buzzing mirror

I had the same problem with my '86 R80RT. At some RPMs the mirrors were louder than the engine. Taking for granted that there wasn't a mechanical fix, I drilled a hole in the bottom of each mirror and injected expanding insulating foam into the hole. The foam expanded against the backs of the insides of the mirrors and either pushed them against the frame or adhered to the backs of the mirrors. Either way, there is no vibration and no noise. I trimmed the excess foam that extruded through the injection hole level with the bottom of the mirrors and also trimmed the foam that came through through the top sides of the mirrors (very little here) and colored the foam black with permanent marker. As the holes are on the underside of the mirrors, you have to be lying on your back to see them, and since they match the mirror housings in color, they are all but invisible. Worked for me. You should put newspaper down under the mirrors because the foam expands to more than twice its initial volume and will fall out of the holes as it expands and sets up. I tried to really pack it in because I knew I only had one shot at applying the foam. The mirrors leaked for about an hour, but I got a goof result.

The expanding foam is a good idea, but if you really want to add mass to the mirror body (and change its vibration characteristic), use clear silicone RTV. This will really do the job.

The foam and silicone are both great ideas for curing a loose mirror. But on my '86 R80RT, the mirror is not loose..the whole right side mirror assembly virbrates. I even had to replace the plastic nut cap at the bottom of the mirror 'cause the vibration literally shook it off!! Don't have near the vibration on the left side.

Hawk Hawthorne
VP BMW MOA