1981 R100RS Diaphragm Spring Height

[SteveD]

Looks like I have the non undoing petrol cap syndrome.
I just found out about this on another BMW forum.
Two fixes were mentioned

1. Pulling it open with a rope through the handle?
2. Dilling a hole in the cap and inserting a self tapper
to lock the inner workings to the outside of the cap

Does anyone have details of where to drill the cap for
the self tapper fix?

Should work. Give it a try before drilling.

[ME 109]

Try pulling the handle up with a rope and at the same time tapping the handle with a large screwdriver handle in the direction to undo.
Worked more than once for me.

[kutter]

Yes it came off by pulling hard upwards on the handle
and unscrewing.
Now I've got it out I can apply the self tapper fix
to lock the mechanism together.
Thanks for the suggestions

[SteveD]

These are the bits and pieces...



If you line the holes up (picture below) and shove something in there to maintain alignment, the cap will not be a problem again. Like the screw from the top method, it holds the lot together. The whole thing is just pressed together otherwise.

[kutter]

Thanks for those pictures Steve.
I also found out why the domed steering head nut
was such a PIA to remove.
I was looking at a diagram of the front forks
in Clymers when it hit me. The forks were assembled
incorrectly by a PO.
Working down from the top it was

1 Domed top nut
2 adjusting locking ring/nut
3 Yoke

Of course it should have been

1 Domed top nut
2 Yoke
3 adjusting locking ring/nut

I don't know how in hell
the proper adjustment on the head
bearings was ever achieved.

Frame should be going in for powdercoating
after Christmas.
I was thinking black (of course) satin or semi-gloss