After I had removed the engine, I removed the clutch to inspect it. Based on the inspection and information I found on Duane Ausherman’s site, I decided to replace the entire clutch.
Here is the web page I wrote up on removing and inspecting the clutch.
I’ll document the installation of a new clutch when I complete the work in another web page.
I’d like to acknowledge folks who regularly participate on the BMW Airhead forum on Micapeak. In particular, Tom Cutter who runs Rubber Chicken Racing Garage and Bob (Snowbum) Fleischer who has a great technical library on all things BMW motorcycles, answered questions I posted on the Micapeak forum and in personal Email and phone conversations. Their knowledge makes the life of a “hobbyist”, such as I, less stressful and much more fun.
Here are a couple of pictures from the web page writeup.
Bar Preventing Rotation When Removing Clutch Bolts
Backing Off Clutch Pressure 1/2 Turn Per Bolt at a Time
Clutch Parts Order: Bottom Clutch Pressure Ring, Top Clutch Diaphragm Spring
Diaphragm Spring Finger-Wear on Edges
Clutch Pressure Plate Facing Engine Showing Grooves from Diaphragm Spring
I thought I would provide a progress report on this project. There has been a lapse in my posts. My wife and I spend six weeks in Europe (all of June) with three of those weeks engaged in “applied motorcycling” as we rode on two guided motorcycle tours. The first was in eastern Europe riding in parts of the former Yugoslavia, Bulgaria and Albania. Here’s my trip report, A Motorcycle Tour of Eastern Europe: “Combat Touring” in the Balkans. And the second was in the Pyrenees and I’ll be posting a trip report on that ride soon.
After returning, there were a number of things to get on top of including a major landscaping project, and all of a sudden, it’s early August. I finally got back into the shop this week and started by reviewing what I had completed so far (see the work plan below).
I was able to remove the clutch and flywheel just before I left for Europe. Upon inspection of the clutch, I decided to replace it. I ordered the parts from Tom Cutter at Rubber Chicken Racing Garage and they came in just before I left. I’ll start work on replacing the rear main seal and oil pump cover o-ring and then getting the flywheel and clutch back into the engine block and I’ll post a web page on that work soon.
I decided to go back to the carburetors and replace the screws on the top covers with new stainless steel ones. Some of the slots in the screws had been enlarged so time to get that taken care of. And, I wanted to add the spring on top of the slide that was included staring in 1977. I’ve heard this improves smoothness and I did the same upgrade to the carburetors in the R75/6 project. I’ll update the carburetor rebuild page to include this.
Here’s the spring and how I installed it.
1977 Carburetor Spring
Carburetor Spring on Top of Slide
Spring Installed Between Slide and Top
I also tried a little trick to ensure the throttle screws on both carburetors are just touching the tab on the throttle shaft. I slipped a piece of paper between the tab and the top of the adjusting screw and then tightened the screw until I could just feel the drag on the paper. I always have a hard time ensuring the screws are evenly touching the tab when the carburetors are mounted, so this way they are even before I install them.
Using Paper To Adjust Throttle Screw So it Just Touches the Tab
Here is the progress on the task list so far. The good news is there are more check marks since the last report in March. But, there are still quite a few tasks to keep me busy 🙂
I posted a web page on this work where I show how I measured the cylinders and pistons to determine the piston-cylinder clearance, the cylinder taper and cylinder ovality. I honed/deglazed the cylinders and installed new rings grinding the ends to set the gaps to the correct specifications.
The measurements didn’t alarm me so I saw no need to bore out the cylinders and replace the pistons. I did use one over size rings to compensate for the cylinder wear and ground the ends down to the specified ring end gap.
Here are a few of the pictures included in the web page write up.
Zeroing Micrometer with 3 inch Reference
Bore Gauge with Dial Indicator
Setting Bore Gauge to Known Distance
Measuring Cylinder Bore Diameter
Wear Pattern Showing Minor Ridge & Polished Section of Bore
