Author Topic: BMW R100 Airhead (Read 40090 times)

Scott S · « **on:** September 14, 2015, 03:18:51 AM »

Yesterday, I traded my XS650 Brat/Scrambler for this '84 R100.
I think that he got the better end of the deal at the moment but, with a little love and attention, the BMW will be worth more in the long run and will fit my needs much better.

The BMW runs pretty good, with no leaks, smoke or weird noises. There's half a mile of play in the throttle, so I'll have to fix that. The rear brake needs attention and there's an intermittent charging issue.
I talked to two trusted friends that know these bikes well (one is a Master Mechanic) and they both, without hesitation, said "Do it! Make the trade!".
The bike came with a new rear brake hose and a brand new set of Michelin tires. The plan is to spend the Winter giving it a full tune up and service, fluids, etc., and getting the charging system up to snuff. Then I'll work on de-ugly-fying it. I need a new seat in a bad way....

I know next to nothing about a BMW. It came with a manual and I can turn a wrench. Are there any good Airhead forums out there? Google returns an overload of results. Several of them require a yearly fee to join. I'm OK with that, as long as it's the best one to join.
Anyone here know these bikes? I'm sure I'll have some questions eventually. It's a quirky bit of German engineering.

Scott S · « **Reply #1 on:** September 14, 2015, 03:22:28 AM »

It has the dual plug heads and, I was told, 40mm exhaust....but it measures out 38mm to me, unless I'm doing it wrong.
There's also supposed to be something special about the kickstand....an option or something?

And it's got these funky, funky bars on it. My initial reaction was to swap them out for a set of Renthal 754 bars that I bought for my ZRX and ended up not using. But the more I sit on the bike, the more I like them. They're pretty narrow, but they seem very comfortable, actually.

martin_uk · « **Reply #2 on:** September 14, 2015, 03:48:34 AM »

I had an R100T a couple of years ago.

Bought it in bits, had twin plug conversion plus bigger oil sump.

Didnt get on with riding experience of shaft drive and gearbox, but do like the style.

2013_0513BMW0003 by nitram2010, on Flickr

2013_0513BMW0025 by nitram2010, on Flickr

2013_0513BMW0006 by nitram2010, on Flickr

Some useful info here

http://bmwmotorcycletech.info/technical-articles-list.htm

Scott S · « **Reply #3 on:** September 14, 2015, 04:08:59 AM »

Airhead.org returns a website for sale type page.

I'm not sold on the yellow. I do love a center stand...might have to look into that. I have so much to learn about these things...

70CB750 · « **Reply #4 on:** September 14, 2015, 05:04:17 AM »

Score!

martin_uk · « **Reply #5 on:** September 14, 2015, 07:59:52 AM »

Quote from: Scott S on September 14, 2015, 04:08:59 AM

Airhead.org returns a website for sale type page.

I'm not sold on the yellow. I do love a center stand...might have to look into that. I have so much to learn about these things...

On my R100 I had to help the centre stand up with my foot each time, even with new springs, but was told it is normal.

Roach Carver · « **Reply #6 on:** September 14, 2015, 08:07:46 AM »

Adv forum has a section just for airheads. If you can't find it I will link it for you. Very nice score. I have had an xs650 and a few bmw airheads. I would never trade one of my airheads for an xs. Just my opinion of course but i think you did well. Like cal said, there are 3 or 4 tools you need but they are not that expensive and some you can make yourself.

jeffg · « **Reply #7 on:** September 14, 2015, 02:55:25 PM »

that's real nice looking.

Stev-o · « **Reply #8 on:** September 14, 2015, 04:10:34 PM »

Congrats Scott. You really got Cal excited over there!

simon#42 · « **Reply #9 on:** September 15, 2015, 01:03:09 PM »

Quote from: calj737 on September 15, 2015, 04:42:32 AM

Quote from: Stev-o on September 14, 2015, 04:10:34 PM
Congrats Scott. You really got Cal excited over there!
Only because I've got one too that's undergoing a major renovation, modification I've ridden plenty of airheads, but have never owned one, so I'm pretty stoked to finally have one. Maybe by next summer mine will be done and on the road. $:-\$

about time you bought a proper bm cal , as everyone on this forum knows real bikes have carbs !

scott , i think it was you that got the better end of that deal .

srbakker · « **Reply #10 on:** September 21, 2015, 02:06:46 PM »

What a beauty! Can't wait to see it all cleaned up and going cross country.

Scott S · « **Reply #11 on:** October 07, 2015, 03:51:43 AM »

The first order of business is to get my newly acquired center stand installed. I'm told its a Reynolds Ride Off stand and I got it and the hardware from a member here.
Just holding it up and eye balling things. it looks like maybe the left ear on the frame is bent or tweaked. Is this common? Am I going to have a hard time getting it straightened out?

Next, the hardware I got has the two spring holders, #17 in this pic.

It looks like they go up top on the frame. The spring mounts on the frame are VERY tight to the engine case. Will I be able to slip the spring holders (#17) up and onto the tabs? Please tell me that I don't have to lift the engine up to install these holders.....

Any tips or tricks for installing a center stand?

Scott S · « **Reply #12 on:** October 07, 2015, 03:52:07 AM »

My sorta-kinda plan of attack:

* Pick up exhaust tool at Barber...and maybe a few other goodies if I run across them

* Install center stand

* Adjust valves and retorque heads

* Pull bodywork so I can tidy up the wiring and have better access to "stuff"

* Fluids.....oil/filter, rear end, etc. Basically all the drive train fluids.

* Check timing

* Work on sloppy carb cable(s) and sync/adjust carbs

* Look into charging system for cause of low charging problem. Repair as needed.

* Install new rear brake hose and flush brake fluid front and rear

* Detail wheels and have new tires mounted

After that, I'll have a properly running, charging and stopping bike. Then I'll focus on the cosmetics and getting the luggage repairs done. I'd like to wire the bike up for an auxiliary port for my phone/GPS and probably some riding/fog lights.

I'll be asking about all that stuff and plenty more as we go along.

Scott S · « **Reply #13 on:** October 07, 2015, 04:31:25 AM »

Question: It doesn't look like I can get the ears on my jack up to the frame rails. Would it me OK to use the stand on the sump? Not to really lift the bike.....only to get it upright so that I can work around the center stand brackets, etc.

Scott S · « **Reply #14 on:** October 07, 2015, 05:01:55 AM »

PM sent.

Scott S · « **Reply #15 on:** October 07, 2015, 11:37:46 AM »

It's really hard to get a pic, but the LH ear IS warped a little bit.

This is how the center stand fits on the RH side:

And this is the LH side:

The good news is that I can get it on ears and I have the bolts started. I think it will pull on up and be OK. I have two minor hang ups, though...
First, I need to get a shorter 6mm allen wrench so that I can tighten the bolts. I'm not going to sacrifice my good set, but I need to cut off the short part at the 90 degree bend so I can hold the bolt and tighten the nut.

Second, there is absolutely no way that the hangers will fit without removing the engine. Max BMW lists three springs for the '84 R100; a 97mm (which I have and is intended to be used with the spring holders), a 143mm and a 111mm. I think that if I had the 143mm spring then it would work.

Scott S · « **Reply #16 on:** October 07, 2015, 01:50:05 PM »

Thanks, Cal. You're the best.
Someone suggested loosening the front and rear engine bolts and seeing if I could pry the frame out enough to get the hangers started, too.

Scott S · « **Reply #17 on:** October 14, 2015, 03:25:31 PM »

A local guy had the same stand and same spring and extender thing set-up I have. I just see no way to get it installed without moving the engine around. I ordered a couple of longer springs and will try that. If that doesn't work, I'll try something else.

I also got the valves adjusted. Both exhausts were fine, both intakes a little loose.

I also traded my Day Long seat for a nice stock seat and I exchanged a few beers for a set of crash bars. Woo-Hoo!

One thing that I'm going to have to work on is why the throttle has so much play in it. We took the RH control apart and checked the little gear/chain assembly there and tried moving it around a tooth, but it didn't help. When I twist the throttle up at the grip, it moves nearly an inch before anything happens down at the carbs. I haven't pulled the tank yet, but is there adjustment down there where the cable splits that may take up some slack? Or do I just need a new cable?

How often do you Airhead guys replace the rubber grommets on the intakes? If it ain't broke....

Roach Carver · « **Reply #18 on:** October 15, 2015, 09:03:06 AM »

The adjustment is on the carb bodies although an inch sounds like a lot. The gear in the throttle will wear an cause notchiness but should not cause that much play. On the rubber parts. If they look cracked I would replace. They are not too expensive if I remember correctly.

78whiteorbs · « **Reply #19 on:** October 19, 2015, 03:13:24 PM »

Hey Scott just got another 1 !
Check it- 10k miles all original near perfect condition weird pipe blueing got me scratching my head.....

It's an 80 r65 minus the weird pipe blueing I cant find a thing wrong with this bike,it's like brand new.

I know usually lean condition would cause this but normally wouldnt be that far down and the header isnt that bad strangely.

Roach Carver · « **Reply #20 on:** October 19, 2015, 06:27:59 PM »

I am not sure about the r65 but some of the snick and wheels were recalled and replaced with reinforced versions. http://bmwmotorcycletech.info/19inchrecall.html

Scott S · « **Reply #21 on:** October 23, 2015, 04:24:01 PM »

I got the exhaust hangers installed properly and, along the way, the Brown side stand.

The center stand went on easy with the new, longer springs.

I need to make a stop so that it won't hit the side stand when it's up.

The center stand is surprisingly easy to use. The bike pops right up with minimal effort and is very stable. The rear wheel isn't quite off the ground, but nothing a block of wood under the stand wouldn't fix. I'm happy!
Now....on to the fluid changes...

Scott S · « **Reply #22 on:** October 23, 2015, 04:26:15 PM »

I also mocked up the crash bars. I really dig this style. The plan is to eventually mount some riding/fog lights on them.

Scott S · « **Reply #23 on:** October 24, 2015, 05:03:59 AM »

I haven't done anything with the exhaust flanges yet.....did you mean the hangers?

I saw a few bumpers in the parts fiche at MaxBMW, but they were called side stand bumpers or kick start bumpers.

Am I supposed to have #12 in this pic?

Or something like #11 in this pic?

I can totally see something like #11 in the 2nd pic bolted to the center stand working.

Scott S · « **Reply #24 on:** October 24, 2015, 05:22:25 AM »

No....for some reason the hangers were loose. The Brown side stand uses the hanger on the LH side for the front mount. Straightened all that out while installing the center stand.

News:

Author Topic: BMW R100 Airhead (Read 40090 times)