Vintage BMW Motorcycle Owners

Strike that, I have jump started it once when hot to get going. Thanks for getting me thinking on that.

Ziggy,
In another thread you said your clutch is slipping and then you just mentioned your bike revving uncontrollably at the point of losing power. Is it possible your engine is running fine and it just can't get power to the wheel because of your clutch?

How does the engine seem to be running when you lose power? Does it sound rough? Is it cutting out? Or does it sound like it's running well but just doesn't make you go?

-Jon

After 2 generous calls with Bench Mark today, the loss of power looks to be two things: inspection of the original advance unit revealed weights have significant lateral play and, the timing is retarded. So timing will be sorted and then to see about the advance.

Are you running an original coil or a Emerald Isle Blue? My R60/2 had all kinds of hot running weirdness and lack of power and bad hot starts until I replaced the old coil. The epoxy in those things is rotten and constantly shorting especially when hot. Since they never even made a real "new" coil for it after 1980, it's an easy place to start diagnostics. For years they repaired them with rewinding but even those are now simply falling apart.

It is running a new Emerald Isle Blue. And, to be sure the coil was not the issue, ran the bike with the magneto exposed in 40 degree weather with 15 mph winds and the symptom persisted.....

The newer Emerald Isle coils had a second ground point included...I think the single ground was an issue with the earlier versions.

Check mag ignition timing. Mine would run great until I got to higher RPMS. Check point gap, static and dynamic timing, to confirm the advance is working. Retarded timing, or late advance will lead to under power at higher RPMs.

Icarus

Today checked point gap - remains at proper setting. Used a timing light and got the bike timed at idle, but at higher rpm strobe would stop working. Took the bike out for a short run and again, stumbled after 7/8 miles when at the top of 2nd. Increase the throttle but no power. I am at a loss. Am I looking for a solution in the wrong place? The fact that it runs great until it heats up makes me think heat is also a factor? Would a slipping clutch present like this?

Maybe something is going on with your points/advance. Could it be that the advance unit is severely worn that your getting erratic ignition. And maybe the points are sloppy to the point that at higher RPMs, they bounce around and don't open/close consistently.

I am going to take the advance off tomorrow and inspect. While it is still on the bike are there any simple diagnostics I could do to determine its general condition? And, once off, will overly worn lobes be obvious?