Well, all the work on the rear of the engine is finished as I have completed installing a new clutch provided for free from Euro MotoElectrics who offered to provide free parts for this charity rebuild project to benefit the Motorcycle Relief Project.

Here is the link to the document about how I did this work.

• 21 BMW 1983 R80ST Install Clutch

I also shot a short video summarizing the work.

VIDEO: 1983 BMW R80ST Install Clutch

Here are some before and after pictures of the clutch. This one should be good for the next 100,000 miles.

Original R80ST Clutch Looks Very Bedraggled

Original Clutch Condition

New EME Supplied Clutch Pack Assembled For Installation On Face Of Flywheel

New Clutch Installed

I’ve removed the airbox, transmission, clutch and flywheel to gain access to the rear main seal so I can replace it. You can see how I did that work here.

• 13 BMW 1983 R80ST Remove Air Box & Pulse Air System
• 23 BMW 1983 R80ST Remove Transmission
• 21 BMW 1983 R80ST Remove Clutch
• 11 BMW 1983 R80ST Remove Flywheel

I’ve published documents on replacing the rear main seal on other projects. Here are links to those documents.

• 11 BMW 1983 R100RS Remove Flywheel & Rear Main Seal
• 11 BMW 1983 R100RS Install Rear Main Seal, Oil Pump Cover & O-ring
• 11 BMW 1977 R100RS Replace Rear Main Seal & Oil Pump Cover O-Ring
• 11 BMW 1975 R75/6 Replace Crankshaft Rear Oil Seal, Oil Pump Cover & O-ring
• 11 BMW 1973 R75/5 Remove & Install Flywheel, Replace Rear Main Seal, Oil Pump Cover & Cover O-Ring

Since the 1983 R80ST engine is similar in many ways to the 1983 R100RS, I link to the 1983 R100RS documents as appropriate in this document.

• 11 BMW 1983 R80ST Replace Rear Main Seal

And here is a short YouTube video showing the procedure.

VIDEO: 1983 BMW R80ST Replace Rear Main Seal

I had a real problem removing the seal on this bike using my usual approach with the Cycle Works rear main seal tool, and had to resort to using “a bigger hammer”. I used a hook seal puller to pry the old rear main seal out of the bore. Since the bike has been sitting for 25-30 years, the seal was really stuck in the bore.

Cycle Works Rear Main Seal Tool

Using Hook Seal Puller To Remove Rear Main Seal

Using Flashlight To Verify Seal Is Flush With Case

I’ve removed the airbox, transmission, clutch and flywheel to gain access to the oil pump. You can see how I did that work here.

• 13 BMW 1983 R80ST Remove Air Box & Pulse Air System
• 23 BMW 1983 R80ST Remove Transmission
• 21 BMW 1983 R80ST Remove Clutch
• 11 BMW 1983 R80ST Remove Flywheel

I’ve published documents on removing, inspecting and installing the oil pump on other projects. Here are links to those documents.

• 11 BMW 1977 R100RS Replace Rear Main Seal & Oil Pump Cover O-Ring
• 11 BMW 1983 R100RS Remove & Inspect Oil Pump
• 11 BMW 1983 R100RS Install Rear Main Seal, Oil Pump Cover & O-ring

Here is the link to how I do the work on the 1983 R80ST.

• 11 BMW 1983 R80ST Remove, Inspect, Install Oil Pump

And, here is a short video that summarizes how I do this work.

VIDEO: 1983 BMW R80ST Remove And Inspect Oil Pump

Oil Pump Cover Removed

Oil Pump Rotors Marked With “F” For Front Face

Oil Pump Measurements – They Are All Good

Since this project bike was not running when I picked it up and had been sitting outside for awhile, I don’t know what components of the electrical system work. So I remove the starter motor and test it.

What The 1983 R80ST Looked Like When I Found It

Here is the link to the documentation on how I do this work and a short YouTube summary of the process.

• 12 BMW R80ST Remove And Test Starter Motor

VIDEO: 1983 BMW R80ST Remove And Test Starter Motor

The good news is the starter motor was in good condition and worked correctly.   I cleaned up the starter motor and the top engine compartment it sits in.

Starter Motor Nose Refinished

Front Starter Motor Bracket Refinished

Top Engine Housing Is Clean