1983 BMW R100RS/RT First Engine Start

The first engine start is always a major milestone on a project. I usually perform this earlier in the build than I am on this project. But, my gas tank and the other parts that I had painted have been delayed coming back, so I’ve done everything else I can do until I got the gas tank in hand. This Friday, I picked it up and installed it.

I made a detailed check list prior to starting the engine so I wouldn’t forget something and improve the likelihood the engine will start.

Here is a link to the procedure I followed to prepare for the engine start, and how I performed the all important initial bedding in of the new piston rings with the new Nikasil coated  cylinders.

I also made a summary video of the procedure and recorded the engine start.

VIDEO: 1983 BMW R100RS/RT First Engine Start

 

1983 BMW R100RS Install Carburetors, Cables And Air Box

I show how I remove the carburetors and airbox in this write-up.

Since I am converting this RS model to an RT, the handlebar throttle and choke cables have to be longer and I show how to change the handlebar cables in the Bowden assembly. I installed them when I installed the handlebar perches as shown here.

I had the air box powder coated. Although the carburetor rebuild was a couple years ago, I rode the bike less than 1,500 miles after the rebuild and they have been off the bike for about two years. I inspected the o-rings and found they are in good condition so no need to do another carburetor rebuild.

Since I modified the engine to boost compression from 8.2:1 to 9.5:1 and had the heads bored for dual spark plugs, I have to change the carburetor jetting. This engine has the same configuration as the engine in my 1977 R100RS that has the CFO (California, Florida, Oregon) configuration, so I use the same carburetor jetting.

When I first got the bike, I rebuilt the carburetors and “updated” the pulse-air system that fed air to the exhaust ports as shown here.

Here is how I did the work.

And this is a video summary of the procedure.

VIDEO: 1983 R100RS Install Carburetors, Cables And Air Box

Here are a few pictures from the write-up.

Air Box Top, Air Filter And Air Box

Air Box Top, Air Filter And Air Box

Air Box Internal Parts And Fittings

Air Box Internal Parts And Fittings

Air Box Fittings

Air Box Fittings

Air Horn Plastic Pipes Attach To Tee With Wire Spring Clamps

Air Horn Plastic Pipes Attach To Tee With Wire Spring Clamps

Snap Clips Into Air Box Cover Slots

Snap Clips Into Air Box Cover Slots

Choke Cable Bowden Connector Housing Routing Under Starter Relay (Left Side)

Choke Cable Bowden Connector Housing Routing Under Starter Relay (Left Side)

Throttle Cable Bowden Connector Routing Next To Frame On Top Of Voltage Regulator (Right Side)

Throttle Cable Bowden Connector Routing Next To Frame On Top Of Voltage Regulator (Right Side)

Richer 170 Main Jet Installed In Jet Carrier

Richer 170 Main Jet Installed In Jet Carrier

Adjust Throttle Stop Screw So It Just Contacts Throttle Arm Using A Piece Of Paper

Adjust Throttle Stop Screw So It Just Contacts Throttle Arm Using A Piece Of Paper

All Done-Left Side

All Done-Left Side

All Done-Right Side

All Done-Right Side

All Done-Top

All Done-Top

 

1983 BWM R100RS Install Center And Side Stands

I am not using the stock side stand for three reasons: the bushing and bolt are trash, it’s in an inconvenient location hidden by the cylinder and lower fairing panel when extended making it hard to deploy, and the bike came with a Brown’s side stand which mounts further back on the frame so it’s easy to deploy. The left exhaust header bracket is secured to the Brown’s side stand bracket so I installed the side stand when I installed the exhaust system.

Brown's Side Stand

Brown’s Side Stand

Brown's Side Stand Installed

Brown’s Side Stand Installed

I had the center stand repaired and powder coated. I replaced the pivot bolts and bushings due to wear and tear.

Center Stand Wear and Tear After 82,000 Miles And 37 Years

Center Stand Wear and Tear After 82,000 Miles And 37 Years

Repaired And Powder Coated Center Stand

Repaired And Powder Coated Center Stand

Here is a link showing I do this work.

I take the bike off the lift test out both stands. It’s nice to have it on the center stand again đŸ™‚

Side Stand Works

Side Stand Works

Center Stand Works

Center Stand Works

1983 BMW R100RS Install Exhaust System

Putting the mufflers on this bike is exhausting. [laugh track]. Okay, I just couldn’t resist that one.

I decided to replace the exhaust system due to the amount of corrosion I found on the original one. This year/model bike has two cross-over pipes while the earlier year airheads (before the 1981 model year, or before 09/1980) had a single cross-over pipe beneath the front engine cover. The rumor is the second cross-over pipe improves engine performance over the single pipe models. I got the exhaust system from Euro MotoElectrics

I also install the Brown’s side stand that came with the bike as it attaches to the left side header bracket and the front hole of the side stand bracket uses special bolt and nut supplied with the side stand. There is also a toothed washer for the rear hole that mounts on the rear engine stud with the standard nut to keep the side stand bracket from rotating on the engine stud.

Here is a link to the detailed installation procedure and a short video summary of the installation.

VIDEO: 1983 BMW R100RS Install Exhaust System

Here are some pictures.

Header & Cross-Over Pipes From EME

Header & Cross-Over Pipes From EME

Front Header Pipe (Top) Is Longer Than Rear Pipe (Bottom)

Front Header Pipe (Top) Is Longer Than Rear Pipe (Bottom)

Exhaust Header Hardware

Exhaust Header Hardware

Brown's Side Stand Installed

Brown’s Side Stand Installed

New Muffler Installed

New Muffler Installed

New Headers And Cross-Over Installed

New Headers And Cross-Over Installed

 

1983 BMW R100RS Install Steering Damper Mechanism

Installation of the steering damper mechanism is straight forward. One thing that you can get wrong is aligning the number on the damper rod with the correct position of the damper rack it adjusts. I show how to get that orientation correct.

Here is the link to the detailed procedure and to a short video summary of the installation process.

VIDEO: 1983 BMW R100RS Install Steering Damper Mechanism