Vintage BMW Motorcycle Owners

Welcome! I would certainly consider greasing the transmission input splines. I would also be sure you clutch adjustment is correct. You should have 5-6mm of free movement of the shift lever at the back of the transmission and you should also have some free play at the hand lever.

Welcome to the forum! If you go to RealOEM.com, enter your 7-digit number into spot on the page...in your case those digits are 0066690. RealOEM comes back with a build date of July 1991.

My '69 R69S also has the rivet friction surfaces. I suspect the one that is glued is less costly to produce so that's likely what they're offering now.

Craig - I'm not sure but we may be talking past each other. I never mentioned a multi-vis oil. I was comparing something like a 40w engine oil viscosity to that of a 90w gear oil. They must have relatively the same viscosity. I suggest that because BMW went from specing 40w engine oil in transmissio...

Viscosity systems for engine oil and gear oil are different. So 40/50 weight engine oil is about the same viscosity as 80/90 weight gear oil. Gear oil should only be used if you have installed the proper seals as identified by BMW in their service bulletins. That's pretty drastic to have all the oil...

Not sure the carb number is all that important...it's the jets etc. that are important. Of course, you've increased the amount of air being pulled into the engine...could be that with not real changes to the carbs, there's less fuel provided to go with that air. Typically, the idle circuit is only m...

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...