Page 1 of 1

1977 R100 gas tank cap

Posted: Mon May 04, 2020 1:10 pm
by comet
I have a problem removing my gas cap. I haven't locked the gas cap on my 77 R100 for years. I tried locking it today and yes it locked but when I unlocked it I could not remove the cap from the tank. The cap spun counter clockwise or clockwise but would not engage the threads in the tank. Has anyone else had this problem and what was the fix? Thanks for any help........Comet

I've read that you're better

Posted: Mon May 04, 2020 2:24 pm
by schrader7032
I've read that you're better off not locking these caps...the ratcheting mechanism can fail...they're not really like the cap on a car.

Snowbum discusses it at the top of this page:

https://bmwmotorcycletech.info/fuel-caps-airheads-K.htm

First try the belt/rope trick while standing over the bike on the pegs. Run it through the handle and provide some gentle up pressure while you try turning the unlocked cap off. If that doesn't work, follow the instructions on drilling a hole to release the mechanism.

Gas Cap Problem

Posted: Mon May 04, 2020 3:19 pm
by comet
Thanks Schrader, I guess I am not the only one with that problem. I appreciate your help. Comet

/7 Gas Cap

Posted: Tue May 05, 2020 10:33 am
by Carott
Comet,
If your gas cap spins without resistance in both directions that is the locked position.
In the unlocked position there is usually a ratcheting sound when you tighten it after it bottoms out. If it makes a ratcheting sound when you turn it counterclockwise the mechanism has probably failed.
When the cap seems "locked" and will not move to unscrew it usually means that the threaded portion of the cap is stuck in the threads of the tank. Penetrating oil and gentle persuasion are your best bet.
If the cap makes the ratcheting sound when trying to unscrew it the the belt trick is the way to go.
Good luck,
Brett

anoton's article

Posted: Tue May 05, 2020 11:13 am
by lauffer6996
Anton's article might help as well.....
http://largiader.com/articles/gascap/

Thanks, everybody......Comet

Posted: Tue May 05, 2020 5:30 pm
by comet
Thanks, everybody......Comet