My Airhead Needs Help - Airheads Beemer Club Forum https://www.airheads.org/community/my-airhead-needs-help/ Airheads Beemer Club Discussion Board en-US Wed, 01 Jul 2026 08:16:52 +0000 wpForo 60 R65 LS not charging https://www.airheads.org/community/my-airhead-needs-help/r65-ls-not-charging/ Wed, 17 Jun 2026 00:14:05 +0000 Since last season my '82 R65 LS hasn't been charging every time I go for a ride. Thankfully bump starting is a cinch. I checked the connections to the stator etc and all looks good. All new parts in there too. After similar issues on my Moto Guzzi that turned out to be a toasted battery I'm thinking this might the same issue with my R65. I know the same battery has been in the bike for many years so it wouldn't be any surprise. Now it's just a matter of looking up what the replacement is and try that. The Goose was solved with a new one. 

]]> My Airhead Needs Help Mike Buhler https://www.airheads.org/community/my-airhead-needs-help/r65-ls-not-charging/ 1981 R100RT Transmission repair service https://www.airheads.org/community/my-airhead-needs-help/1981-r100rt-transmission-repair-service/ Sat, 23 May 2026 18:48:05 +0000 I live near Detroit and I'm seeking a Trans rebuild service that does good work that might be near. I've got about 80K on the bike and at present have a broken shifter pawl spring. Makes since to do what's needed while it's open. Considering shipping it to Barrington motor works but wondering if there could be some other nearer options as well.

]]> My Airhead Needs Help Lee Nyboer https://www.airheads.org/community/my-airhead-needs-help/1981-r100rt-transmission-repair-service/ Hard Starting https://www.airheads.org/community/my-airhead-needs-help/hard-starting/ Sun, 10 May 2026 14:38:34 +0000 I am haveing a hell of time getting my 1985 R80RT started after having the carbs rebuilt and engine desmogged. Hopebully this video works and you can hear what is going on.  I have checked the valves and float bowls for debris.  I'm at a loss as to why it will eventually start, but starts so rough and hard.  Right now I really don't trust it for a longer ride.

 

https://drive.google.com/file/d/1RDN-RUHCeS_ln62M0uRFGCMtyQacfvjN/view?usp=sharing

]]> My Airhead Needs Help Curtis Nugent https://www.airheads.org/community/my-airhead-needs-help/hard-starting/ Centrifugal governor removal https://www.airheads.org/community/my-airhead-needs-help/centrifugal-governor-removal/ Thu, 07 May 2026 18:01:09 +0000 I wanted a project bike so I obtained my first airhead. 1977 R75/R. That's what all the documentation says and all the serial numbers agree. The front cover looks like it might have a 1975 or 76 ignition sensor, it has the centrifugal governor. Doesn't show that on the 1977 fiche I have been looking at. The cover has 3 holes instead of 2 also as stated on the fiche. Did BMW mix/match? Attached is a picture. Anyway, how do you remove it?

]]> My Airhead Needs Help Tim Cubbedge https://www.airheads.org/community/my-airhead-needs-help/centrifugal-governor-removal/ '74 r90s Idle Problem https://www.airheads.org/community/my-airhead-needs-help/74-r90s-idle-problem/ Wed, 29 Apr 2026 13:10:48 +0000 Looking for some guidance on my BMW R90S. I’ve been chasing an idle issue that seems to be getting more inconsistent, and I’m starting to wonder if I’ve got more than just a tuning problem.

Background:

Originally (before any clutch work), the bike was idling a bit low. I tried adjusting it, but had a hard time getting it to hold around ~1,000 RPM consistently. Once fully warmed up, I could sometimes get it close, but it would dip and stumble, and I’d see the generator light flicker like it wanted to stall. I often had to give it a little throttle to keep it alive.

Clutch repair:

I recently replaced the clutch cable. That’s now working great, no issues there.

After that, I thought I had the idle somewhat sorted around ~1,000 RPM.

New behavior:

On a recent ride, I noticed the idle climbing higher than expected, about 2000rpms. When I got back and put it on the center stand (still running), I tried to dial the idle back down, but:

  • The idle screws felt extremely touchy
  • Small adjustments made big changes
  • I couldn’t get it to settle consistently
  • I’m not confident I properly “reset” the idle screws from a true baseline

At this point, I’m not sure I’m correctly identifying when the idle screw is actually making contact internally vs just free play, so I may be chasing my tail there.

Current issue:

Right now, unless I keep the idle set relatively high, the bike wants to stall when I try to bring it down near ~1,000 RPM.

Additional observation (possibly related):

Yesterday, after running the bike and shutting it down, I put it on the center stand and realized I had left both petcocks on.

About 10 minutes later:

  • Left side looked normal
  • On the right side, I could see what looked like continuous fuel bubbling in the small glass area above the carb

I shut the petcocks off immediately.

Appreciate any guidance. I’m trying to be methodical here and not make things worse by guessing.

Keeping it real, if there were a spectrum of folks who are experienced and knowledgeable airhead mechanics, if it's not obvious, I'm pretty low on that spectrum. I have the original service manual as well as a copy of both a Clymer's and Hayne's manual. AI is a great resource for finding what I'm looking for as well. I came here, because on my clutch repair, some kind fellas helped me dial right into what needed to happen.

***Additional observation.....when I turn the throttle it does not snap back....it usually makes it's way back eventually, but not immediately and consistently. Sometimes I have to turn it back myself***

]]> My Airhead Needs Help Lance Mark https://www.airheads.org/community/my-airhead-needs-help/74-r90s-idle-problem/ Red charging light https://www.airheads.org/community/my-airhead-needs-help/red-charging-light/ Mon, 27 Apr 2026 13:01:53 +0000 1978 R100/7 : all components within the charging system are new and functioning correctly, strong battery, brushes/springs in good order, clean rotor surfaces, no loose wires up in the Speedo/tach housing, etc. etc.

The problem: the red charging light will go on, albeit a slight flicker on again/off again with the bike running at 3000 plus RPM. Not at lower RPM, just the mid-upper end of the tachometer range.

The light goes on when the key is turned on, goes out once the bike is started, as it should.

Problem existed before and after installing a Katdash for the bike.

Any thoughts?

]]> My Airhead Needs Help Anthony Fodero https://www.airheads.org/community/my-airhead-needs-help/red-charging-light/ Compression question https://www.airheads.org/community/my-airhead-needs-help/compression-question/ Sun, 12 Apr 2026 17:47:33 +0000 Hello, 

Ive been having trouble syncing my carbs. The left cylinder pulls way more vacuum than the other, so the manometer won’t level at all. The carbs were just rebuilt by Bing. I did a compression test and it was strange. I saw online to remove the carbs first before testing, so I did both:

with carbs on, no filter: L=65 R=120

without carbs on: L=130 R=125

what on earth is going on??

thanks!

]]> My Airhead Needs Help Blake Wester https://www.airheads.org/community/my-airhead-needs-help/compression-question/ Generator Lights Performing Opposite Of Expected https://www.airheads.org/community/my-airhead-needs-help/generator-lights-performing-opposite-of-expected/ Tue, 07 Apr 2026 02:30:59 +0000 Over this past winter I spent a fair amount of time doing some upgrades to my '77 R100/7. Mostly doing handling, braking and cosmetic modifications. However, once the bike was back together and I started it for the first time, I've noticed an issue that wasn't there before. My generator light isn't behaving as it should. In fact, it seems to be doing nearly the opposite of what it should. At idle, the light goes off and once I'm on the throttle it comes on very brightly. Also, when I turn on the ignition, the generator light is also bright, as it should be.

My first thought was to pick up Rick Jones Classic Boxer Charging to see if it would lend some insight. In reading through his book, it seemed like my Voltage Regulator may have been the issue. But, I swapped out, what I believe to be a functional, used voltage regulator, and it did the same thing.

In full disclosure, I had one of the moments when putting the bike back together, that makes me feel a little less than bright. Fairly recently, I replaced the battery with a MotoBat. They seem highly regarded and I've been really pleased with it. However, these batteries have 4 connection points rather than 2. And I found out the hard way then the connections aren't symetrical.  Obviously, I wasn't paying close enough attention when reinstalling the battery and had it sitting in the cradle backwards. I attached the positive terminal first and then when attempting to hook up the negative terminal, I was treated to an impressive sparks show. It took me a minute to figure out what I had done. I then swapped the terminals, turned on the ignition switch and everything seemed to work as it should. 

This past weekend is when I finally had the bike ready for its first spin. It started just fine and seems to run with no apparent issues, other than the generator light burning brightly as I motor down the road. I'm wondering if I have fried the diode board or maybe something else. Any sagely advice would be greatly appreciated. 

Much appreciated. 

Bombadil

]]> My Airhead Needs Help J.T. Sutton https://www.airheads.org/community/my-airhead-needs-help/generator-lights-performing-opposite-of-expected/ Voltage spikes on R100GS https://www.airheads.org/community/my-airhead-needs-help/voltage-spikes-on-r100gs/ Fri, 27 Mar 2026 21:18:29 +0000 Hello fellow AIRHEADS,

Longtime lurker, I just joined the community today.  My 1988 R100GSPD Bumblebee has remained stock for 27 years of ownership, but I never took the beast too far off road.  Pick it up 4x in sand or mud and you will start looking for weight savings...

DURABOOST lithium ion battery shows 13.3V at the terminals.  Rev to 3000 and the voltage spikes all over the place.  28V 30V?  Scrambled numbers hard to read on multimeter.  Collective wisdom here says it's the VR.

Yesterday, my AIRHEAD friend emailed this same question to you experts, and the team answered the call!  "BP", Dave F. and others responded to my pal via AIRMAIL, and steered me in the right direction.

Thank you for the quick responses and suggestions for a solution.  Voltage Regulator replacement in the mail.

-Chris "Big Bird" Ryan

 

]]> My Airhead Needs Help 4dPerspective@gmail.com https://www.airheads.org/community/my-airhead-needs-help/voltage-spikes-on-r100gs/ Stuck valve cover https://www.airheads.org/community/my-airhead-needs-help/stuck-valve-cover/ Sat, 21 Mar 2026 17:06:49 +0000 Hey guys, have any of you had any issues with a stuck valve cover? Looks like previous owner used some kind of sealant. I’ve been trying for two hours now, using wooden wedges but nothing. Just a little gap. I can’t figure out the problem! 

]]> My Airhead Needs Help Blake Wester https://www.airheads.org/community/my-airhead-needs-help/stuck-valve-cover/