BMW Airheads Salton Sea Overnighter

I finally have the rear main leaking seal debacle cleared up as the "new" rear main seal was the culprit. I replaced the seal and also installed a stock flywheel and got rid of the lightened wheel which was on the engine.....next will be a new timing chain as I'm fairly certain the chain is sloppy due to a erratic timing mark.....but first a road trip.....



The Airheads Club "Salton Sea over nighter" was held last weekend. we opted to head over on Friday to make it a two night affair. A number of other riders had the same idea so we had company.

One other BMW airhead motorcycle other than mine was present the first night. A real nice R65. Saturday a large contingent of riders came in to bring the total population to around 30 in the "Outback" area.

Three Goldwings / trailers came in accompanied by a three wheeled "whatever you call it". The Goldwing guys have the camping thing figured out with folding wooden table and anything else you can think of.
We took it very easy and went for a nice soak in one of the multiple hot pools at the site. One of our buddies cooked up a great dinner on Friday night and we carried on with BS sessions well into the night.
The Montana Air Flag made its' appearance as well as the So. Cal. Flag which showed up Saturday night.
The weather was perfect with high 70's and hardly a drop of wind.
B. Jan Hoffman, the Airheads Founder found his way there too.....
All in all it was a very laid back relaxing weekend....now we're planning for the Death Valley Rendezvous coming up in a couple of weeks. That trip will be a week - ten day run for us. We'll head up into Nevada and then over to Furnace Creek....then of to who knows where for a few days. Our trip planning is open and will be dependent on where the best weather is.
The old "Rat'tle trap" performed well other than the new clutch cable breaking after only 100 miles. I've ordered a new timing chain which I will pick up this weekend and get it installed before Death Valley. I'm seeing a jumping timing mark and some "odd" noises coming from the engine when it's hot....pretty sure the timing chain is at its' last gasp of life. I'll change it before something catastrophic occurs....
Met a few new folks at the campout and ran into quite a few old pals too.
Really a great get together even though it was short.....

3rd. Times a charm?

Put a few miles on the bike after the 2nd. transmission removal with the hope that the rear seal might "seat" and quit leaking...no such chance.

Local bombing range in my back yard.



So I pulled the bike apart for the third time to replace the new rear seal with a replacement seal. The new seal material looked "healthier" than the one I installed previously. I also obtained a stock flywheel to replace the lightened flywheel which was on the bike. I removed the oil pump o-ring again to check it and it looked fine. I replaced it with a new one.

The newest seal:

The old oil pump o-ring and the first "new" seal.
Here is the lightened flywheel which I swapped out. Someone spent a lot of hours machining this fellow years back. I've never seen one taken this far.
The bike seems to idle steadier with the stock flywheel in place. I ran it a few miles yesterday after re-assembly and so far so good...no leaks.
I started the tear down at around 1:00 PM and had the bike back together and running at around 5:30. Flywheel removal is getting to be routine. Hopefully I won't have to do it for a while.....don't need any more practice at this point.

Sidecar Road Test

Sidehack rig back in one piece....for the time being anyway.....

Ran a short run up the freeway yesterday to road test the hack. The K-Block tires definately change the handling characteristics of the bike. There's now a lot more contact with the pavement. The ride is better with a passenger and / or load in the hack.

After a 25 mile run at freeway speed I stopped to look things over and see oil seepage from the transmission area. So either the rear main seal is still leaking or the oil pump seal is leaking. I'm leaning towards the rear main seal......I've read that new rear main seals can weep a bit initially when replaced so we'll see. I'll change the oil next week and add some seal conditioner and hopefully the seepage will stop. I don't cherish the thought of pulling the whole damn bike apart again....

I was going to start tearing down the R75/5 to part it out on EBay. Decided to list it as a running project bike to see what might happen. I'll be damned but my $1k. reserve was met and the bike will sell as is. I hated to tear apart a running bike anyway. Someone will have a good foundation to build a Cafe bike or ride it as a Rat bike. The bike is fun to ride as is.

I have a few other misc. used BMW parts listed too. Appears that the "after Christmas" BMW parts market is alive and well.

K-Block Sidecar Tires for BMW

On the road again.

Ran about 10 miles around the neighborhood today and all appears a-ok....no oil leaks and the new k-block tires are a instant handling improvement.

We've been busy, busy, busy since mid December. Including a couple weeks in Montana, then a 3 day camping trip with the Airheads BMW Club for New Years at Agua Caliente in the CA. desert.

I tore down the BMW and needed a couple of weeks to get all the parts together.
Finally acquired all the needed clutch parts. I had made plans to swap with another BMW guy to change the "lightened" flywheel for a stock flywheel but he didn't follow through with sending the flywheel. Not wanting to wait another week for a flywheel I decided to re-install the "lightened" unit.
I installed all new parts and found the old rear main seal loose in the housing and was able to remove it with no tools. The new rear main seal went in without a hitch. The crankshaft MUST be blocked from moving forward when the flywheel is removed. The oil pump cover o-ring was changed also. I couldn't really tell which seal the oil was leaking from.
Considering the fit of the old rear main seal, it likely was leaking from there.

The engine / clutch went together in one day and yesterday I spent swapping tires around.

I cleaned up the exhaust system / installed and refitted the sidecar mounting sub frame, airboxes, battery box, etc.

I had a pair of Michelin "K-Block" 18" sidecar tires and then acquired a 19" Avon sidecar tire for the front. I was able to modify my sidecar axle configuration to accept the 18" Sputnick wheel I had, but did not attempt to install the brake assembly. I purchased the Sputnick wheel / hub a few years ago and the near new K-Block tires were part of the deal. They appear to be nearly new and the rubber was still supple and not hard. I didn't want to run the K-Blocks until I had a set of three. Until recently I never saw that Avon offered a 19" K-block tire, they are frightfully expensive compared to the cheap tires I've been running.

The front k-block tire was a tight fit to the fender and I had to change out a couple of fender mounting bolts and remove the rear rubber cushion spacers for the fender mount to gain minimal clearance.


The tires went on easily with no problems and then I installed the battery to run the engine up. The motor fired up with the touch of the switch and ran great. No oil leaks evident after 15 - 20 minutes of run time. The bike is not ridable solo due to the tires and front end Earls fork....I guess a person could ride it but I didn't think it would be advisable.


The 18" Sputnick wheel is much heavier built with larger spokes and brand new bearings. It also has a Alloy hub cover to keep dust out of the bearing area.

Many sidecar riders use K-Block tires but many say that they aren't necessary. I wanted to see if I can gain more mileage from them in the wear department. I typically wear out a rear tire before 3000 miles and a front tire about 3000 miles. The K-Block tires cost about double the conventional tires so they need to gain a lot more wear miles to be ahead of the game.

The big square tires will definately put more rubber on the road and might effect my fuel mileage negatively, we'll see....

Today I'll mount the sidecar back up and should have the old girl ready for a test run.

So we'll have new "shoes", a complete new clutch assembly and a refreshed engine top end.

I also had found a pair of "Marzzochi" rear shocks for dirt cheap a while back. I was going to use them on my now "defunct" /5 project so decided to install them on the hack. They are an air assist shock, in Italian Red, lol.

I want to run a few hundred shake down miles to be sure the sidecar axle will perform properly and will need to re-torque the cylinder heads after a hundred miles or so.

"WW2 BMW" .....NOT

Our trip into the mountains of CA didn't end up too sucessful in this latest quest.
What was described as a WW2 BMW side car rig ended up being an old Russian bike.


I'm not sure of the year as I'm no expert on these bikes. It was obviously old and had a dismembered flathead side valve engine.

The side car frame was probably the most valuable part of the find.

The side car tire:

Pretty husky old frame with leaf springs.

The remains of the rusty old drive train.

Someone had written "BMW" on a Russian piston.

She had the manual "nuetral finder" lever...maybe had a reverse too?

Poor old thing.....the frame is remarkably like my old Zundapp KS601 I sold this summer.

So, I'm back on the hunt for my next great "find".

BMW R100S Clutch and top end assembly

I retreived the newly rebuilt cylinder heads in San Diego yesterday so decided to assemble the engine top end this morning. When I originally pulled the R100S engine apart, years ago, it had cylinder base metal gaskets installed. Unfortunately I tossed them thinking that new ones would be used. I then found out that the base gaskets were not used on these engines. The later engines had an "o-ring" groove on the cylinders for sealing. This engine had no o-ring grooves so sealant was necessary to seal the cylinder to the engine.
I want to reduce the engine compression a bit so I purchased a pair of earlier base gaskets and then trimmed down the interior diameter to fit over the engine cyliders. All I have is a small Dremel type tool so I spent probably an hour on each gasket, trimming down the interior diameter to fit over the cylinder base.
Hopefully the base gasket will not reduce the compression too much. I saw signs of detonation on one piston so reducing the compression should hopefully make the engine run a little cooler and get rid of any "pinging".

The base gasket in place prior to cylinder head installation.

I cleaned up the pistons / ring grooves well before installing them in the cylinders. There are also a couple of o-rings on two of the cylinder studs. I made sure they were properly in place before installing the heads. I previously had pinched one of the o-rings causing a minor cylinder base leak.

Brand new Black Diamond Valves, Valve Seats and o-ring valve guides.

I actually spent more time modifying the base gaskets than it took me to assemble the engine top end.

I then turned my attention to the clutch assembly. I ordered a set of special bolts needed to back off the pressure plate assembly. Once the clutch came out I was in awe that it even worked. Two big chuncks were missing from each side. The pressure ring / pressure plate are grooved and worn down. This unfortunate developement will require replacing everything in the clutch assembly....to the tune of $500.00 or so.....

Suprisingly the fly wheel has been lightened and balanced.

Dream on.....?

So...we'll be digging through old dirty shipping containers tomorrow to unearth an old WW2 motorcycle and sidecar...anyway that is according to the present owner.





I have no idea what we will find....or even if it actually is a WW2 German motorcycle.


Apparantly this bike / sidecar was sitting in an old semi trailer for eons, where the previous owner stashed it. The semi trailer was an on old 40's "art deco" looking rounded affair that someone wanted so bad that they purchased a shipping container and hauled it to the property to replace the old "deco" semi trailer.


At some point the sidecar was removed from the bike so it would fit in its' storage space.


I talked with the owner this morning and he said we might have to do a little digging in the storage containers to find everything.


Sounds like fun to me!





Maybe it is an old Zundapp KS800?


Or maybe a old BMW R12?

Ooohhhh...or maybe an R75?

Or maybe an old Zundapp KS750?

Tomorrow will tell.......I'll have my camera and notebook handy to record serial numbers....or maybe I'll need my Chinese / Russian Dictionary.....

Update coming in a day or two...

Cheers

WW2 BMW ?

I've finally had phone contact with the landowner who claims to have a WW2 BMW sidecar rig.
The gentileman contacted me through a Craigslist "wanted" ad.

The currant owner purchased a large section of property which the old owner had spent years filling full of junk. The new owner has spent the past year or so clearing all the junk out.
An old semi trailer there held a bunch of old Harley Davidson parts / bikes which the guy sold.
Also in the trailer was this (supposedly) old WW2 BMW motorcycle and sidecar.
It is possible the bike could be an old Russian bike or possibly an old Chinese bike but you never know. The owner had a friend do a little research but never did pin down exactly what it is.
We have made arrangements to meet the land owner there next Tuesday to look things over.
The sidecar is separated from the bike and hopefully things aren't scattered too far and wide.

These kind of finds don't come along but once in a life time, if it is in fact, a WW2 Military sidecar rig. I'll definately take my camera but not the trailer on this trip.
The place is only about 2.5 hours from my house so I can always make a trip over with a proper trailer if the bike is a legitimate military bike and if we can come to a price agreement....a lot of "IFS"....
I'll update the story as things develope.

The Rat Tug under the knife

I finally decided to address the oil leaks which have sprung up on the R100S engine. I've had a cylinder base leak for quite some time and recently the engine started losing oil from behind the transmission. Probably the rear main seal.(?) Started the "dissection" at around 10:00 AM and spent an hour or so just removing body pieces. The side car comes off pretty quickly due to the "pinned" connections. Fuel tank , seat, windscreen, saddle bags, exhaust system came off next.

I've removed parts from this bike enough times to have it down to a pretty quick scenario.

The transmission came off to reveal quite a clean area showing where the oil has been flowing out. On our last road trip the clutch slipped while pulling a long grade. A sure sign of oil on the clutch plate.

I ordered a set of bolts which facilitate the removal of the clutch assembly. The diaphragm spring must be released in stages to avoid warping things and also getting a face full of parts when it comes "springing" off.

I also wanted to address a cylinder base leak so pulled the top end off after removing the transmission. I found a "squished" head bolt o-ring which I botched when I assembled the engine a couple years ago. I will install a pair of metal base gaskets upon re assembly which will slightly reduce the compression ratio and assure cylinder base sealing.



My next surprise was finding a recessed exhaust valve on the right cylinder. This answers the problem I had with valve adjustment issues which were required too regularly.

The cylinders still look good but there is quite a bit of carbon build up on the pistons and cylinder heads.

I made a call to Mesa AZ. to an Airhead friendly repair shop. The heads will be shipped over to them for reworking. hopefully the rebuild won't break the bank.

I also placed an order for all the seals / gaskets needed and a new clutch plate since mine is likely oil soaked.

Todays progress took about 4 hours to completely tear the bike down. I'll likely remove the engine from the frame to allow easier acess to the clutch assembly. I'm fairly certain the engine will need a new timing chain but I'll address the oil leaks / clutch first.

The crankshaft must be blocked into place whill working on the clutch assembly. This requires blocking the crankshaft behind the timing/front engine cover to keep it from moving forward, which can allow a bearing to fall off it's locating pins which open a huge can of worms.

Any timing chain issues will be addressed after the rear engine seal issues are taken care of.

I've had some correspondance with a land owner an hour or so away who claims to have a WW2 German Sidecar rig which he may be willing to sell.

The story goes:

He bought this ranch property years back and there was some old Harley stuff and an old WW2 German sidecar rig in an out building. He sold the Harley parts to some Harley guys and they offered him $2000.00 for the sidecar rig at that time. He decided to keep the sidecar rig for a possible future project. He never got around to the project so it still sits.

I'm hoping to make arrangements to get over to the place in the next week or so to see what he has. He has never tried to sell the bike and has never researched it.

Maybe it will be an ultimate barn find? Who knows.....