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

 

1983 BMW R80ST Replace Connecting Rod Crankshaft Bearings; Replace Oil Pan & Oil Pump Suction Gaskets

Since this bike sat for more than 25 years and I found water in the oil pan, I replaced the connecting rod bearings and the oil pan and oil pump suction gaskets. The bearings were in good condition, so that was a relief. The oil pump suction gasket was brittle so it was time to replace it. None of the oil pan bolt threads were stripped, so that was a good thing. I also had the oil pan, that was painted orange by a previous owner, vapor blasted by the Colorado Vapor Blasting division of Vintage Twins, a local independent shop in my hometown of Arvada, CO. When I told them I was going to auction this bike and donate all the proceeds to the Motorcycle Relief Project, they generously provided me a nice discount on the work. 🙂

Here is a before and after picture of the oil pan.

The Original Orange Oil Pan

The Original Orange Oil Pan

All Done With Vapor Blasted Oil Pan

All Done With Vapor Blasted Oil Pan

All Done With Vapor Blasted Oil Pan

All Done With Vapor Blasted Oil Pan

You can read about how I do this work and see a short summary video here.

VIDEO: 1983 BMW R80ST Replace Connecting Rod Crankshaft Bearings

VIDEO: 1983 BMW R80ST Replace Oil Pan and Oil Pump Suction Flange Gasket

1983 BMW R80ST Replace Timing Chain, Crankshaft Timing Sprocket & Nose Bearing

This “project” bike has over 63,000 miles on it. It’s not uncommon for the timing chain and crankshaft sprocket to wear enough at that mileage to affect valve timing. Too much slack causes uneven timing of the valves. If valve timing varies, then ignition timing will not be optimal. In situations with a lot of wear, the chain can be heard slapping inside the motor. As I’ve never heard this bike run, I do not know if the timing chain is that loose, but that much slop in the timing chain is more common at 100,000+ miles on the chain.

I repainted the inner timing cover and you can read about that work here:

Here is a link to the document showing how I do this work and some videos summarizing the work.

VIDEO: 1983 BMW R80ST Remove Timing Chain, Crankshaft Sprocket & Nose Bearing

VIDEO: 1983 BMW R80ST Install Crankshaft Sprocket And Nose Bearing

VIDEO: 1983 BMW R80ST Install Timing Chain

VIDEO: 1983 BMW R80ST Install Inner Timing Cover