Vintage BMW Motorcycle Owners

In case you wanted those by grades: 1A Amsoil M/T Fluid MTF 5W-30 1A Light Orange Red Line MT-90 75W-90 GL4 1A Light Orange 1B Amsoil Long Life FGR 75W-90 GL5 1B Dark Orange Amsoil Severe Gr SVG 75W-90 GL5 1B Dark Orange Amsoil MT & Gear MTG 75W-90 GL4 1B Dark Orange Castrol Hypoy C 80W-90 GL5 1...

Have done a compression test? What about a leak-down test? They would give you some clues as to where the problem was. But if you can't drive 100 miles without fouling a plug, that's going to get expensive!!

You could experiment with hotter plugs...I think they tend to burn some of that stuff off.

What are the current jet/carb settings? Is there a way you can test for wide open throttle response? In other words, do you have more throttle to turn but the bike won't go any faster? If so, then you need a bigger main jet. But likely you might look at the needle jet and jet needle. The first thing...

I don't think the leak has anything to do with engine breathing. The transmission has its own cavity and it's own fluids. Could be that the engine speedometer bolt isn't breathing and building up too much pressure inside. This seal is well above the top of the fluid sitting in the sump, so it's leak...

The last picture does seem to show it all. I'd say that is oil fouled.

Can you take good closeup pictures of the two spark plugs so we can see what they look like?

Outstanding! Thanks for reporting back!

I'm not sure that it is the change interval on engine oil that should drive your decision. You want a specific weight oil for the temperature for it's viscosity effects. The viscosity of the oil allows it to flow easily for all areas of operation. You want oil flowing as it is what is keeping the me...

Welcome to the forum! I'm not family with this rev counter. Who did you buy it from? Could they provide some guidance? My first thought would be that the ground is not solid enough. Maybe reach out to Siebenrock, too?

Never tried a drag-n-drop on this forum...not sure if it works. The standard way is to click on the Attachments tab at the bottom of the screen, then click on Add Files. From there navigate to where the files are on your computer. I would recommend that they not be huge...maybe 1Mb each would be fine.