I replaced the timing chain, crankshaft sprocket and nose bearing and the three oil seals in the timing chest cover. You can read about this work here:

• 11 BMW 1977 R100RS Replace Timing Chain, Crankshaft Timing Gear & Nose Bearing

The procedure for the 1977 R100RS is the same as the 1975 R75/6 as no major changes in these components was made. I link to the appropriate R75/6 procedures and show differences I found in the R100RS as appropriate.

I did this work in conjunction with replacing the major engine electrical componets. You can read about that work here.

• 12 BMW 1977 R100RS Install Dyna III Electronic Ignition-Refurbish Automatic Timing Unit (ATU)
• 12 BMW 1977 R100RS Refurbish Starter Motor
• 12 BMW 1977 R100RS Replace Engine Electrical Components

Here are a few pictures and videos from the write-up.

Timing Chest Cover Exposed with Cover Puller on Crankshaft Nose

Tachometer Drive Shaft Coming Loose

Timing Chain After Using Bolt Cutter

Dial Indicator Mounted To Check Cam Nose Run Out

VIDEO: Checking Camshaft Nose Runout

Timing Marks When Sprockets Are One Tooth Out of Alignment

Timing Chest Cover Installed

I’ve been making good progress on this project. I’ve finally finished writing up the major engine electrical component replacement and refurbishing the starter motor. You can find this material here.

• 12 BMW 1977 R100RS Replace Engine Electrical Components
• 12 BMW 1977 R100RS Install Dyna III Electronic Ignition-Refurbish Automatic Timing Unit (ATU)
• 12 BMW 1977 R100RS Refurbish Starter Motor

Where the procedure is similar or identical to work I’ve done on other bikes, I link to the existing write-ups and document the condition I found on this bike.

The body work should be back from the painter soon and the hard bits got dropped off for powder coating Tuesday. The clutch was shipped to Southland Clutch yesterday. I’ve got at least one source for anodizing the brake calipers. So a lot of the “outsourced” work is in progress.

Here are a couple pictures from these write-ups.

Engine Electrical Components

Wires on Back of Diode Board

Unsoldering 3-Phase Wires from Terminal Block

New EME Stator

Diode Board, Alternator and Wiring Installed

Dyna III Electronic Ignition

Points Housing Full of Crud

ATU is Rusty

ATU Main Components Disassembled

Old Advance Springs Installed on Cam Plate Pins to Limit Full Advance

New Dyna III Sleeve and Pickup Plate Installed in Points Housing

Starter Motor

Rusty Starter Motor with Cob Webs

Cracked Insulation on (+) Battery Cable; “Red” Wire Wrapped with Electrical Tape

Field Coil Housing Removed Showing Armature

Brush & Coil Spring Detail in Brush Holder

Painted Starter Motor

Due to a lot of cracks in the top middle fairing panel that surrounds the headlight and the fact the upper fairing bracket had both tabs broken that secure the strap that bolts to the steering head, I wanted to check the frame to see if it is straight. I borrowed a frame jig from a long time BMW mechanic who is now retired and used it to see what’s up.  The good news is the frame is straight “enough” for my purposes. 🙂

You can read about how I did this work here.

• 46 1977 BMW R100RS Check If Frame Is Bent

Duane Auscherman has a nice page that describes a technique you can use to check if a frame is bent and it does not require this jig. I included a link to his web page in the above write-up.

Here are a few pictures of the frame jig in use.

Frame Jig

Jig Orientation & Steering Head Bar

Frame Jig Installed in Steering Head

Swing Arm Locating Pin Inserted In Rear of Jig

Swing Arm Pin Centered In Right Swing Arm Bushing

Swing Arm Locating Pin Off Center in Left Swing Arm Bushing By 2-4 mm GOOD ENOUGH 🙂

I wrote up how I removed all the body work on this bike. I discovered a broken upper fairing bracket that was held on with only a hose clamp. There was a broken plastic boss with a threaded insert and numerous cracks and other damage to the fairing panels and side covers. I repaired all of them except for the top center panel that goes around the headlight. The damage was significant with a multitude of hairline cracks and I opted to buy a used panel rather than risk cracks showing up in the paint work after I tried to repair it.

Here are links to the write-ups.

• 46 BMW 1977 R100RS Remove, Disassemble Bodywork
• 46 BMW 1977 R100RS Repair Fairing Panels & Side Covers

I’m ready to start removing the forks and working my way towards the rear as I strip it down to the frame. Then I can see what other surprises are in store 🙂

Here are a couple pictures from the write-ups.

Windscreen Damage

Tapping Drill Bit with Plastic Hammer to Drive Center Pin Out of Windscreen Rivet

Windscreen Removed

Carefully Drilling Inside of Dash Rivet

Dash Removed From Fairing Panels

Broken Upper Fairing Bracket Steering Stem Mount

Fairing Panels Removed

Headlight Panel Badly Broken

Headlight Panel Lower Right Corner Badly Damaged

Top Left Side Panel with Large Crack

Top Left Side Panel Cracks Routed Out with Dremel Tool

Top Left Side Panel After Plast-aid Repair and Sanding

Bottom Right Side Panel Repair to Brass Insert Boss

Brass Insert Final Hole Size-5/16″

Testing Integrity of Boss & Brass Insert Repair

I picked this bike up in April 2016. Finally, on September 1, I got started on it. I had to finish up work on the 1975 R75/6 “S” update and completed that in July. I’ve put about 600 miles on that bike and its running well. You can see all the work I’ve done on the R75/6 here:

• 1975 R75/6 Rebuild: Project Index

I wrote up a project page and added my build plan. You can find these here:

• 1977 BMW R100RS Rebuild: Project Index
  • 00 BMW 1977 R100RS Planning the Build

My goal is to complete the build by September 1, 2017 so I can ride the bike to the 40th anniversary get together in Pennsylvania later in September.

I will be posting a write-up on how I repaired the numerous cracks and broken parts on the fairing panels soon.

Here’s what I brought home, and what it looks like in the shop now.  Progress is being made.

“10 Foot” View

“10 Foot” View

“10 Foot” View

10 Foot View

Body Work & Wheels Removed