New brake fuild, wrapping up

Well , it is the end of October, I put the carbs, and brakes, and front wheel all back together now.

I added brake fluid, DOT 3, which is recommended by Clymer and the forums. I bleed the brakes, and it feels pretty good, no bubbles in the line. I will test ride, and bleed a little more if necessary. I put the tank back on and took it for a test ride.

The carbs need adjusting quickly, since putting all new cables, etc on. This is my next procedure, build a carb stick and balance them until she purrs.

Rebuild Front Wheel Bearings

I'm very proud of this next maintenance items, not because it was hard to do, but it is the first procedure where I actually made my own tool to perform the work. After reading the posts online, the front wheel bearing cap on my R100S has four small holes in the cap that requires a tool to be inserted into to it to unscrew the polished cap. The posts warn about not using a screw drive or nail to perform this task of screwing the cap, the cap is fairly large so it needs to be done right.

Following the Airhead canyons of do it cheap, I cut a 1x1 strip of scrap wood about two feet long, enough to get some leverage., I then measure the holes on the cap and drilled some small holes in the center of the wood that aligned with the cap. I took some small sheet metal bolts and inserted them into two of the holes so they were protruding out from the wood, but enough grab in the wood not to move.

I inserted the tool into the cap, and leftty loosey waa laa, she unscrewed with a bit of torque. I would love to work on machines all day if it paid what the IT industry would.

I cleaned up the bearings, the grease had gone pretty brown, cleaned the bearings out with Gunk cleaner, than simple green, a good rinse, and blew them out with air. I proceeded to lube with Moly past, pout all the spacers back together, and man did the front wheel glide. After I put them wheel back on I could not believe the free play in the wheel. I have left the brake calipers loose since the rebuild until this part was completed.

INSERT PICTURE OF TOOL HERE

New Front brakes

I ordered new caliper kits for the dual front disc brakes, these are dust covers, and seals, and new pads, Freedo brake pads from the BeemerShop to be exact

While I had the front wheel off I decided to inspect the front wheel bearings and relube using the proper grease.

I drained all the brake fluid, and got to work on the front end.

The brake caliper pistons and the inside were very clean, very little work, no scratches on the pistons, and the internal groove of each piston was remarkably clean.

From the Beemershop

"When BMW switched from the original non-metallic Jurid pad to the semi-metallic Textar pad, there was a noticeable improvement in braking power. Those pads are still available from BMW, but they are very expensive. Ferodo Platinum Series pads are constructed similar to the BMW Textar pad at a fraction of the cost. Fits all 74-80 models EXCEPT R65. The only semi-metallic aftermarket brake pads available for the /6/7 series. Provides longer life and better stopping power with a slight increase in rotor wear. Recommend new o-ring and clip which are not included, but we have them in stock."

New Throttle Cables

Since I just re-did the carbs, and choke cables, before I put them back on the bike I installed new throttle cables.

At this point, I have replaced all the cables minus the new brake cable I ordered.

New carb kit, choke, and throttle cables.

I'm in the process of making a carb sync tool, since everything will have to be synced given all these new parts.

New Carb Rebuild

Time to rebuild the carbs today, my carb rebuild came in the mail

• New Diaphrams
• New Gaskets
• New O-rings
  

I did noticed that the left carb ran much smoother, I did one at a time, between test rides.

Here is the kit visually

New Clutch Cable

I installed a new clutch cable today, boy what a difference the new bowden cable made, I adjusted to the proper feel, with no slippage, it made such a difference in shifting from first to second.

New Plugs Bosch W5DC Copper Core

I installed new spark plugs today, man bike started right up, first try with choke. The old NGK plugs did not look that bad, and I will save for emergency road trip parts, but at least I know they are new, and original Bosch plugs to boot.

Bing Carb Numbers

In preparing to order Bing rebuild kits, I came across conflicting information about my 1977 R100S. Some of the third party online parts suppliers have my carbs listed as 32mm carbs, others listed as 40mm carbs.

The Beemershop showed me where the numbers are, man they are hard to read. On mine they are located on the left webbing area right below the cover, they are stamped vertically, and mine were not stamped deep. The "/" slahes alomst look like 1's if your aware this is the format X/Y/Z.

Mine are 40mm carbs, like I thought, but it is worth checking, measure twice, buy once.


Left Carb
94/40/103

Right Carb
94/40/104

Reference:

Bing Link

Good Vibrations

Real Progress

A short 40 mins test ride, no stumbling, no lurching, no stalling, very slight popping on engine braking, but not load or consistent. I might have somewhat corrected the fuel issue. On the next ride, I will pull over at random times, and check fuel level in bowls just to see if the absense of screens is realing making a difference.

Next problem, is why the low vibration at all speeds. Idle is rough, Plug replacement, and check gap spacing is next test, of course one at a time to see if the new plugs will help.

Tranny Drink

Continuing my maintenance list, I had order some Redline Transmission fluid, not a difficult task, not necessary given the unknown maintenance this bike had.

While draining the old gear oil, I realized I forgot to get a new crush washer for the drain plug. I have a new filler plug crush washer, hopefully it will not leak much.

One quart of Redline 75W90 synthetic oil, and about 10 mins later were good to go.

Note
Old oil did not look bad at all. Magnet drain plug had a bit of black paste, and some small flakes.

Fuel Petcock Screens

Since my stumbling, lurching issue started, I want to test if this was a fuel flow issue.

The Test Ride
I went for a short ride, various speed, after about 10 mins, the bike lurched, and begin its usual crappy ride. I pulled over, gave it about 2 mins for carbs to fill back up and continued on. I rode another 10 mins, and the bike still was lurching, this time I had only one petcock on, the left, I quickly reached down turned it off, and pulled over.

The left carb bowl was about 1/3 full, and the right about half. I left the petcocks on, and it would not start, until I let the bowls fill back up. At this point the carbs are not synced, so it might be running lean or rich, but it did seem as though my issue is fuel flow.

Fuel gas cap is venting, so I decided to check the new petcock screens. I proceeded to let the bike cool off, and then drain the fuel, the left side seemed slower than the right as the fuel flowed out of the petcocks. I cleaned them out,, there was some red flakes coming out of the petcock tops, and reinstalled minus the small lower screens. I left the top straw screen on, since i know the tank is flaking a bit.



This tank is due for flush out, repair, and paint, but for now I will try riding without lower screens to see if this helps.