32 BMW 1983 R100RS Replace Choke and Throttle Cables

When I did the inspection of the bike, the throttle and choke cables looked pretty worn with kinks showing in the outer armor. The Bowden connector rubber boots are disintegrating. I’m replacing the cables before riding the bike as I don’t want a stuck throttle or broken cable to happen.

Parts List

I ordered the following from MAX BMW.

Part # Description Qty
32 73 1 242 593 CHOKE CABLE – L=671MM (from 09/80), To Handlebar 1
32 73 1 242 139 CHOKE CABLE – L=531MM (from 09/80), To Carburetors 2
32 73 1 242 128 ACCELERATOR BOWDEN CABLE-L=675MM (from 09/80), To Handlebar 1
32 73 1 242 135 ACCELERATOR BOWDEN CABLE-L=517,5MM (from 09/80), To Carburetors 2
32 73 2 301 342 Choke/Throttle Bowden PROTECTION CAP 2

Removing Choke Cables

The 1983 R100RS has a handlebar operated choke instead of the one mounted to the left side air box cover.

Choke Lever on Top of Left Handlebar Controls

Choke Lever on Top of Left Handlebar Controls

A single cable from the handle bar lever pulls a plug inside the Bowden connector to which is connected the two cables that go to the carburetor choke assemblies.

To start, I remove the plastic cover on top of the choke lever using a utility knife to pry the cover up.

Removing Plastic Cover on Choke Lever

Removing Plastic Cover on Choke Lever

Under the cover is a large bolt that attaches the choke lever to the housing.

Plastic Choke Lever Cover and Cam Bolt

Plastic Choke Lever Cover and Cam Bolt

Unscrewing bolt reveals a special washer and the nipple of the choke cable connected to the cam of the choke lever.One of the cable stands in the choke cable is broken, so it certainly is time to replace the cables.

Removing Choke Cam Bolt

Removing Choke Cam Bolt

Choke Lever Removed from Housing

Choke Lever Removed from Housing (Note Broken Strand in Choke Cable)

Cam Bolt with Special Washer

Cover Bolt with Special Washer

I use needle nose pliers to pull the nipple out of the cam.

Pulling Choke Cable from Choke Cam

Pulling Choke Cable from Choke Cam

The cable routes through a slot in the housing.

Choke Cable Routing in Choke Housing (Note Broken Cable Strand)

Choke Cable Routing in Choke Housing (Note Broken Cable Stand)

Removing Choke Cable Through Slot in Choke Housing

Removing Choke Cable Through Slot in Choke Housing

Once the handlebar cable is removed from the choke lever, I work on disassembling the Bowden connector. It is on the left side of the frame next to the starter relay with the shredded rubber boot.

Choke Bowden Connector on Left Side

Choke Bowden Connector on Left Side

To open it, I unscrew the end cap that has the two cables going to the carburetor choke assemblies.

Twist End Cap off of Bowden Connector to Expose Cables Inside

Twist End Cap off of Bowden Connector to Expose Cables Inside

Then I screw in the adjuster for the handlebar cable all the way into the Bowden connector so the rubber plug extends outside the Bowden connector.

Rust and Cracked Rubber Boot on Handlebar Cable

Rust and Cracked Rubber Boot on Handlebar Cable

I pull out the plug that connects all three cables together. The handlebar cable is in the middle and the carburetor cables are on the sides of the rubber plug.

Three Cables Connect to Rubber Plug Inside Bowden Connector

Three Cables Connect to Rubber Plug Inside Bowden Connector

I remove the choke cable adjuster from each carburetor so I have slack in the cables.

Removing Carburetor Choke Adjuster

Removing Carburetor Choke Adjuster

I push the carburetor cables out of the plug and pull them through the slots in the rubber plug.

Carburetor Cable Pushed Out of Plug for Removal via Slot

Carburetor Cable Pushed Out of Plug for Removal via Slot

Carburetor Cables Removed from Rubber Plug

Carburetor Cables Removed from Rubber Plug

Then I unscrew the handlebar cable adjuster out of the Bowden connector.

Unscrew Handlebar Adjuster from Bowden Connector

Unscrew Handlebar Adjuster from Bowden Connector

These are the Bowden connector parts. The carburetor cable cap and rubber plug are on top.

Bowden Connector Parts

Bowden Connector Parts

Install New Choke Cables

Here are the new choke cables and Bowden connector rubber boot. The long cable is the handlebar cable and the two shorter ones, which are the same part number, go to the carburetors.

Choke Cable Part Numbers

Choke Cable Part Numbers

Choke Cables-Long is Handlebar Cable

Choke Cables-Long One is Handlebar Cable

I install the new rubber boot on the handlebar cable. I remove the nut on the cable adjuster, spray a little silicone lubricant inside the boot and the slide it over the adjuster. I find twisting it on the threads helps pull it along the adjuster without tearing the small hole. Go slow and it will slide over the adjuster without tearing.

Remove Adjuster Lock Nut on Handlebar Cable to Install Rubber Boot

Remove Adjuster Lock Nut on Handlebar Cable to Install Rubber Boot

Pushing Rubber Boot Over Adjuster

Pushing Rubber Boot Over Adjuster

Rubber Boot Installed

Rubber Boot Installed on Cable

Next, I thread the cable adjuster all the way into the Bowden connector so I have maximum inner cable length available so I can insert it into the middle of the rubber plug.

Handlebar Cable Threaded into Bowden Connector

Handlebar Cable Threaded into Bowden Connector

Threading Handlebar Cable into Center of Plug

Threading Handlebar Cable into Center of Plug

Then I insert the carburetor cables into the plug.

Choke Cables Threaded Into Cable Plug

Choke Cables Threaded Into Cable Plug

I use a little Dry Slide on the cables near the ends and then screw the cap onto the Bowden connector. The Dry Slide evaporates leaving graphite stuck to the steel strands of the cable.

I insert the ferrule into the choke lever cam and grease the cam.

Choke Cable Inserted into Choke Lever Cam

Choke Cable Ferrule Inserted into Choke Lever Cam

Then I route the cable into the choke housing that I also greased.

Choke Cable Inserted Into Handlebar Housing

Choke Cable Inserted Into Handlebar Housing

I attach the choke handle to the housing using the cover screw. Then I back out the handlebar cable adjuster until there is just a little slack in the handlebar cable and then push the rubber boot over the adjuster.

Adjusting  Slack in Handlebar Cable

Adjusting Slack in Handlebar Cable

Assembled Choke Bowden Cable

Assembled Choke Bowden Cable

I insert the carburetor cable adjusters into the carburetor and adjusted the cables at the carburetor so both chokes open at the same time. I make sure the carburetor choke levers are all the way to the stops when the choke is turned off at the lever.

Replacing Throttle Cables

The procedure is the same as for the choke cables except the handlebar throttle assembly is different. I remove the cover screw to expose the cam and chain inside the throttle assembly.  They are completely dry, but should have some grease to lubricate the came assembly and prevent rust.

Remove Throttle Cable Cover

The throttle Bowden connector is on the right side of the frame tube under the voltage regulator.

Right Side-Throttle Bowden Connector

I install the cable ferrule in the end of the chain and attach the cover to the throttle assembly. When I get the handlebar cable installed into the Bowden connector, I use the handlebar cable adjuster to remove most of the slack in the handlebar cable. Then, I install the carburetor cable adjusters in the carburetors and adjust them so the throttle levers move at the same time and there is a little bit of slack.

All done and now I don’t have to worry about a broken cable.

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