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

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

This “project” bike has been sitting for over 25 years. So, for reliability, I’m going to replace the charging system which consists of the alternator, diode board and all associated wiring. I may try to rebuild the electronic ignition sensor, aka, the “bean can” that uses a Hall effect sensor to trigger the ignition. This document covers how I remove the components.

Also, I plan to replace the timing chain, crankshaft timing sprocket and the nose bearing which are behind the inner timing cover that the charging system and electronic ignition sensor are mounted to, so I have to remove all these components before I can remove the inner timing cover.

The original alternator looks a bit bedraggled.

Original Alternator Looks Bedraggled

Original Alternator Looks Bedraggled

I’ve replaced charging systems on other projects. Here are links to those documents.

Here is what the inner timing cover looks like after all the engine electrical components are removed.

Inner Timing Cover After Engine Electrical Components Removed

Inner Timing Cover After Engine Electrical Components Removed

Here is a link to the document showing how I do this work, and a short YouTube video summarizing the work.

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

1983 BMW R80ST Install Flywheel

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.

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

Original R80ST Clutch Looks Very Bedraggled

Original Clutch Condition

Original Clutch Condition

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

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

New Clutch Installed

New Clutch Installed

 

1983 BMW R80ST Install Flywheel

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

I also show how to remove the flywheel here.

I’ve published documents on removing and installing the flywheel on other projects. You can see those documents here.

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

Here is a short YouTube video showing how I do this work.

VIDEO: 1983 BMW R80ST Install Flywheel

Here is how things look now.

Flywheel Installed

Flywheel Installed