1983 BMW R80ST Replace Push Rod Tubes

I had the cylinders vapor blasted. In preparation, I removed the push rod tubes. After they were vapor blasted I install new stainless steel pushrod tubes I got from Euro MotoElectrics, who graciously has agreed to provide the parts for this charity rebuild project for free. I will auction this bike and proceeds will go to the Motorcycle Relief Project.

I have done this work before on my 1983 R100RS rebuild and will reference material from the documentation of that build as appropriate.

Here is what I started with before vapor blasting the cylinders and replacing the push rod tubes.

Original Cylinder And Push Rod Tubes

Original Cylinder And Push Rod Tubes

Here is a link to the documentation and a short YouTube video summarizing the procedure.

VIDEO: 1983 BMW R80ST Replace Push Rod Tubes

This is the final result.

New Stainless Steel Push Rod Tubes Installed In Vapor Blasted Cylinders

New Stainless Steel Push Rod Tubes Installed In Vapor Blasted Cylinders

1983 R80ST Replace Swing Arm Bearings

I removed the swing arm bearings before I had the swing arm powder coated. The swing arm bearings are the same sealed bearings used on the 1983 R100RS that I previously rebuilt, so the procedure for replacing them on the R80ST is the same. In this document I link to the previous documentation for the 1983 R100RS as appropriate.

Here is a short video summarizing the work.

VIDEO: 1983 BMW R80ST Replace Swing Arm Bearings

Earlier versions of the airhead swing arm used traditional bearings with a separate inner and outer race. I show how to replace that style swing arm bearing here.

1983 BMW R80ST Remove & Install Drive Shaft

I had the swing arm powder coated, so I removed the drive shaft before taking it to the powder coater.

The 1983 R80ST swing arm is designed for a monoshock rear suspension, but the driveshaft is the same as the one used in the dual shock 1983 R100RS. I previously removed and installed the driveshaft in a 1983 R100RS and documented the work. So I will not repeat the procedure here, but link to it as appropriate.

1983 R100RS Dual Shock Swing Arm Design

1983 R100RS Dual Shock Swing Arm Design

1983 R80ST Powder Coated Monoshock Swing Arm Design

1983 R80ST Powder Coated Monoshock Swing Arm Design

This is a link to the documentation and a YouTube video showing how I remove and install the drive shaft.

VIDEO: 1983 BMW R80ST Remove & Install Driveshaft

1983 BMW R80ST Cylinder Measurement & Honing

This bike has the Nikasil plated aluminum cylinders. Nikasil is a nickel silicon carbide material that is extremely hard and wears very little and can be platted onto aluminum. That said, I want to measure the cylinders to determine if they are in good condition since the bike sat for about 25 years and had 64,000 miles on it.

Insert Bore Gauge Into Cylinder & Align With Top Measurement Circle

Insert Bore Gauge Into Cylinder & Align With Top Measurement Circle

I previously measured the cylinders on my 1973 R75/5 and you can see that procedure here.

On this bike, I measure the bore, ovality and taper using a bore gauge to see if these cylinders are still serviceable. I found Both cylinders are in good condition.

Bore Gauge Kit

Bore Gauge Kit

After measuring the cylinders I remove the glaze on the cylinder walls using a ball hone. I use the Brush Research Flex-Hone® with 240 grit aluminum-oxide balls that they recommend for Nikasil cylinders. I use a 3-1/2 inch hone and my portable electric drill that has a low speed range of 600 RPM which is within the recommended 500-800 RPM Brush Research recommends.

Brush Research Flex-Hone Ball Hone & Honing Oil {I Bought WAYYYYY Too Much :-) }

Brush Research Flex-Hone Ball Hone & Honing Oil {I Bought WAYYYYY Too Much 🙂 }

After Honing-Good 45 Degree Cross-Hatch

After Honing-Good 45 Degree Cross-Hatch

Here is a link to the document showing all the details of how I do this work and a link to a YouTube video.

VIDEO: 1983 BMW R80ST Cylinder Measurements & Honing

1983 BMW R80ST Install Alternator, Diode Board & Electronic Ignition Sensor

I replaced these components with new ones supplied my Euro MotoElectrics at no cost to me in support of my goal to auction this bike and donate all the proceeds to the Motorcycle Relief Project. EME has been very kind and generous to me on this project.
I installed their new Type 1 charging system kit, the EDL-1 107, which has all the parts to replace the stock 240 watt charging system including a new front crankshaft seal.

I also installed their remanufactured electronic ignition sensor, aka, the “Bean Can”, and a new ignition system sub-harness.

You can read about how I did the work and see a YouTube video.

VIDEO: 1983 BMW R80ST Install Alternator, Diode Board & Electronic Ignition Sensor

This is what I started with.

Original Engine Electrical Components Under The Front Engine Cover

Original Engine Electrical Components Under The Front Engine Cover

Original Diode Board

Original Diode Board

Original Alternator

Original Alternator

Original Bean Can

Original Bean Can

And this is the final result.

All Done

All Done