Stripped Ignition Advancer Bolt on R69S

meredithresidence · Post by **meredithresidence** » Wed Jan 19, 2011 8:18 pm

I own a 1968 BMW R69S. When I try to remove the 6mm bolt which holds the ignition advancer and magneto rotor to the camshaft of my bike, it spins freely in either direction. I suspect the threads of the bolt or the cam or the magneto rotor are stripped. I can get a good grip on the bolt with a pair of vise-grips, but no matter how hard I pull while I'm turning the bolt, I can't get the threads to engage and the bolt just spins around. Does anyone have any idea on how to remove the bolt? Thanks!

Gary

808Airhead · Post by **808Airhead** » Thu Jan 20, 2011 1:13 am

You may have to use a miniature slide hammer setup to pull it out.

schrader7032 · Post by **schrader7032** » Thu Jan 20, 2011 6:40 am

Two words...call Vech at Bench Mark Works...OK, 6 words. Find out what your options are and how those options affect what you'll do after you get the bolt out.

In the 1970-on bikes, when this bolt/nut strips and the advance unit can no longer be held on, I seem to recall two possibilites. One is to drill and tap for a larger size bolt. The other, which is easier to do for the /5-on bikes, is to install an electronic ignition which does away with the mechanical advance unit. In the case of the /2, that can also be done with the ignition system triggering off the crankshaft, not the camshaft. That is actually a superior method as it can greatly reduce the vibration due to differential timing when the camshaft tip is bent or the timing unit becomes worn out.

meredithresidence · Post by **meredithresidence** » Thu Jan 20, 2011 7:32 pm

Thanks for your advice and the advice of 808 Airhead. Much appreciated.