New member and owner 78 r100s

[tsa]

We would prefer that you ask stupid questions first. There is no reason for you to make the same expensive mistakes that we made in the past. Make all new mistakes so that we can learn from you.

+1

Having rebuilt a "water bus" (another local nickname) several times, you should be familiar with bike mechanics. Thus; take the S apart over the winter, and inspect properly for wear. ISTR that storage for decades can cause the engine main oil seals (rear) to dry out, resulting in engine oil leaking all over the clutch the first time you ride it. Hence advice to replace the oil seal first, instead of the oil seal + clutch friction plate later, when you intended to go riding.

Got any service history with it? Unless already done, at 78 kMi the gearbox bearings may need replacing. Also, the exhaust valves and valve guides could be replaced, for peace of mind.

[Snakeoil]

I had that exact color Water Buffalo back when it was just another used bike. It's a '74 if I remember right. I bought it around 1976 or 77. Burnt Orange metal flake paint. Boy did it sparkle when it was out in the sun. I think I paid $400 for it used with no miles on it to speak of.

I'd take a look at the valve cover on the other side and see if they are simply swapped around. Looks like she's been down on that cover at some point in time.

Congrats on getting the bike. At least on the left coast, you can still ride this time of year.

If it sat for 20 years, check out my thread on my '78 R100/7. My bike sat and I found rust inside the layshaft end caps of the tranny as well as some pitting in the left cylinder. NC has worse humidity than we do so better to be safe than sorry. I ended up stripping the tranny apart and replacing all the bearings except the roller. Also found oil/water mix in the drive shaft housing. Rear end was fine.

regards,
Rob

[Airbear]

This is Beatrice, the original back seater.

Was Beatrice sad to see the bike leave?
And what a fine name for the bike.

Your project is one of rescue and conservation. It is a Good Thing to document everything you can, including whatever information you can glean about the bike's history, previous owners, previous work, alterations from stock, and so on. 'Beatrice' is likely to last a very long time with proper care. Future carers of 'Beatrice' will appreciate whatever provenance you can provide.

If your motorcycle mechanical experience is with Japanese bikes you are in for a real treat. BMWs use proper fasteners - robust Allen headed bolts and machine screws - not those nasty JIS screws that are made of cheese. Enjoy!

[Duane Ausherman]

Take many photos. Take more than you can imagine ever needing. You will still want a photo of something that you didn't take. Make a lot of notes in your log book on everything. Lay the parts out in order of removal.

Unless it was stored with pistons at TDC, it is likely to have rust in one cylinder. There is always at least one valve open to the air and humidity. Check for white grunge on the spark plugs. Look in the spark plug hole at the cylinder with a good light before you turn the engine.

On average the transmission should be nearing rebuild time, unless it was run with synthetic oil. You are near the end of valve guide life. The timing chain is nearing "sloppy" running. That is why the history is great to have.

All of these can be fixed. Only the transmission is a challenge. Most owners send them out and for good reason. The top end work can easily be done by a half decent wrench.

Did you string line the frame yet?

[Bamboo812]

Hard to tell, but isn't that a recall front wheel?

[Holysmoke]

Sounds like fun, tear down, send out tranny, replace seals, valve stem guide seals, look for known problem areas...

I poked around on Youtube, do a leak down test? Cut the exhaust nuts off and put new on with copper anti-seize? Based on results of leak down, replace rings, possibly valve job? On the Buffalo I'd send out the crank for check on bearing wear and seals, similar for the Boxer?

So here's the funny part, I've always been attracted to these boxers, but the only BMW I've ever driven was a K75. I imagine they're pretty dissimilar. I went through the same thing with the Buffalo, drawn to it, bought one before ever driving one. I guess I like the looks and the surprise of driving.

How about steering head bearings? Put roller bearings in the buffalo. Swing arm bushings?

What's a recall front wheel, and string line the frame?

Once back together, run a cup of 100LL per tank for lead lubrication?

Rebuild carbs, i.e. disassemble, clean up and replace gaskets?

On my ST1100 it's highly recommended to lube the rear drive spline with Honda moly grease, otherwise wear is highly likely. Anything special about the boxer drive maintenance?

That's probably a good start for probing for information. I really should read old posts. I'm sure much of this is already covered.

My buddy Bob who picked up the bike kept saying that Beatrice always figured she'd get more for the bike. I paid $750.

Thanks,
Ron

[Bamboo812]

Top wheel is recall wheel, bottom is braced replacement. I think BMW will still replace the recall wheel if it is original to the bike.

[melville]

Nice score! The only way to know for sure about these things is to take them all the way apart:

viewtopic.php?f=1&t=148

Airheads have tapered rollers on the head, swingarm, and wheels.
You'll use that Moly 60 on the trans input shaft and the rear wheel splines.

Duane has a website at http://w6rec.com/duane/index.html which is a great resource. It's been a little funny to access lately, though.

http://bmwmotorcycletech.info/ is the astoundingly complete 'Snowbum' site of Airhead info. It can be a little daunting. I usually use it only when I need to know something specific.

[Duane Ausherman]

Melville, I too have trouble sometimes getting to my site. I gotta find the program and try to remember how to fix it.

I would not bother with any type of compression test until it has run for a few hundred miles. The results will be bogus and temporary. It will improve a lot with a few hours on the engine.

[barryh]

WATER BUFFALO!

In the UK they are affectionately known as "Kettles".

The GT750 owners club is even called "The Kettle Club"