I published this document to show how I repair, refinish and paint parts on this project. It contains links to other documents as well as original material. I will be adding to it as I progress with the project.

• 51 BMW R80ST Repair, Refinish & Paint

I just added how I refinished the front engine cover that had a lot of heavy corrosion on it.

Front Engine Cover Corrosion

Front Engine Cover Corrosion

Front Engine Cover Corrosion

Comparing Engine Block To Front Cover: Cover Is Has A Finer Casting So More Shine

I hope this information is useful.

I get a number of questions about how I achieve the “like new” patina on the engine block, transmission and rear drive. I previously published two documents on refinishing, so on this project I decided to create a short YouTube video showing the materials and tools I use and how I restore the aluminum to like new condition without bead blasting the engine block. Blasting the block requires complete disassembly and then meticulous and laborious cleaning of all the oil passages to guarantee no bits of glass are inside.

Here is the document and YouTube video I published. The document contains links to the other two documents about how I refinish various parts.

• 51 BMW 1983 R80ST Refinish Aluminum Engine Block

VIDEO: 1983 BMW R80ST Refinish Aluminum Engine Block

And here are some before and after pictures starting with what the R80ST looked like when I first saw it.

Engine Block & Transmission When I Found The Bike

Engine Block When I Found The Bike

Lower Left Of Engine Block When I Found The Bike

Lower Left Of Engine Block When I Found The Bike

Oil Pan And Bottom Of Transmission When I Found The Bike

Here is what the engine block looked like after I removed it from the frame.

Left Side, Lower Block Still Filthy

Shelf At Rear Of The Block Was Filthy With Thick Gunk I Removed With A Paint Scraper

Right Side, Lower Block Still Filthy

And here is the final result after working about 10 hours over 5 days on refinishing the aluminum block.

All Done-Left Side

All Done-Left Side

All Done-Rear

All Done-Right Side

All Done-Right Side

I hope this is helpful.

Now that I removed the top end, I’m ready to remove the engine from the frame.

Engine Top End Removed

This documents how I do this work with a short YouTube video.

• 11 BMW 1983 R80ST Remove Engine From Frame

VIDEO: 1983 BMW R80ST Remove The Engine From The Frame

I put the engine on my portable motorcycle lift so I can move it around the shop.

Engine Ready For Moving Around The Shop

At this point, I have completed disassembly of the R80ST down to the frame 🙂

Frame

Here is how the bike looks now with all the parts packed in bins.

Bike Disassembled With Parts In Bins

In preparation for removing the engine from the frame, I remove the top end (valve covers, heads, cylinders, wrist pin, cylinders) to reduce the weight. Although not part of the engine top end, I also removed and inspected the cam followers as it is convenient to do that now.

Ready To Remove Top End

This is not the first time I’ve done this. The 1983 R100RS motor is built the same as the 1983 R80ST motor, so the procedure I documented for the 1983 R100RS applies here as well. Rather than duplicate that procedure, here is the link to the documentation on the 1983 R100RS which contains all the details you need to complete this work.

• 11 BMW 1983 R100RS Remove Engine Top End

This document will provide a brief summary of the procedure with pictures of what I found as I did this work on the R80ST engine along with a summary video of this work for the R80ST.

• 11 BMW R80ST Remove Engine Top End & Cam Followers

VIDEO: 1983 R80ST Remove Engine Top End and Cam Followers

And here is the longer video I made for the 1983 R100RS which contains additional information you may find helpful. However, I didn’t show removing the cam followers in this one.

VIDEO: 1983 R100RS Remove Engine Top End

Here is what the bike looks like now.

Engine Top End Removed

Engine Top End Removed

Engine Top End Removed

The transmission on this 1983 R80ST is serial number Z 078854. According to Robert Fleischer’s article on transmissions, the range of transmission serial numbers in 1983 was from Z 074700 to Z 084299, so mine is the original transmission as it is within the range for 1983.

Transmission Serial Number Z 078854

I removed the transmission after removing the battery and battery box, the rear drive, swing arm and monoshock, and the air box and the pulse air and crankcase rebreather components.

Battery Box Removed

Rear Drive, Monoshock & Swing Arm Removed

Air Box With Pulse Air And Crankcase Rebreather Components

Air Box Removed

I found water in the transmission gear lube. The speedometer cable was missing and the hole in the bushing for the cable was plugged with some cloth. Since the bike was outside for awhile, water entered the transmission through the hole in the bushing.

Transmission Has Water In It 🙁

Here is the documentation of how I do this work along with a short YouTube video summarizing the procedure.

• 23 BMW R80ST Remove Transmission

VIDEO: 1983 R80ST Remove Transmission

I am ready to remove the engine. Before I do that I will remove the top end of the engine to reduce the weight.

Transmission Removed