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I Broke My "87 K100RT Today. Suggestions?

Paul_F

RK Ryder
Thought that today would be time to change the washers and gaskets on my '87 K100RT's gas cap.

After removing and replacing washers and gaskets, I reassembled the gas cap components, turned the key to test the locking mechanism before attaching it to the gas tank. Once that was accomplished, I shut it just to be certain that the lock would work, before attaching it to the gas tank.

Well, the lock did not unlock and the tumblers pulled out of the lid. :banghead

Is a new gas cap in my bike's future or is there a fix to unlock it? I know it will definitely will need new tumblers.
 
Thought that today would be time to change the washers and gaskets on my '87 K100RT's gas cap.

After removing and replacing washers and gaskets, I reassembled the gas cap components, turned the key to test the locking mechanism before attaching it to the gas tank. Once that was accomplished, I shut it just to be certain that the lock would work, before attaching it to the gas tank.

Well, the lock did not unlock and the tumblers pulled out of the lid. :banghead

Is a new gas cap in my bike's future or is there a fix to unlock it? I know it will definitely will need new tumblers.

Paul,

Post pictures. It sounds salvageable.





:dance:dance:dance
 
You probably aren't to this point yet as your first step should be to try and get the original tumbler back in to open the cap (unless one or both of the two pins on the end of it are broken off). If they are, try inserting the tips of some small needle nose pliers into the coresponding holes in the lock and turning. Be careful not to bugger up the holes! Remember, the lock rotates COUNTER clockwise.

Worst case:

If you are trying to open a cap that is off the bike (lost key, bought off eBay with no key, lock broke after rebuild but haven't reinstalled, etc.):

Drill a small (1/8" should do) hole at the very front of the filler ring just below the flange. Angle the hole slightly up towards the cap.
DO NOT DRILL ALL THE WAY THROUGH! Stop drilling when you hit the tongue of the latch. The latch is steel, the flange is aluminum.
Just drill a little at a time and check. Use a nail or a punch to push the latch in. Fill with fuel resistant epoxy when done.


P1020199.jpg


P1020198.jpg




:dance:dance:dance
 
Thank you Lee. This is an alternate solution to the first link. I have posted pictures over at
https://forums.bmwmoa.org/showthread...Stuck-Fuel-Cap.

There is nothing to grab with long nose pliers. This solution looks as it might be the way that I'll go. :thumb

Cheers!

Paul,

If you look into the hole in the cap where the tumbler goes, you SHOULD see two small round recesses where the pins on the back of the tumbler engages the locking mechanism. They may have the broken off pins from the tumbler in them. You might be able to drill or pick them out. It is these recesses/holes that you need to engage with the tips of small needlenose pliers or a made up tool and rotate counterclockwise.
The recesses are less than 1/8" dia. and less than 1/8" deep. Don't enlarge them as then they won't work with a new tumbler.





:dance:dance:dance
 
Paul,

Just saw your pictures. One the pins is broken off the end of your lock cylinder (tumbler). You will need a new one:
51 25 1 455 109 LOCK CYLINDER WITH KEY $43.09

Once you get the new cylinder, you can rekey it to your ignition key before you install it. I will post the rekeying process as soon as I get my scanner working (later today or tomorrow).


You will need to clean out the recesses as mentioned in the previous post.





:dance:dance:dance
 
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Paul,

Here is the Service Bulletin from BMW on how to remove Integral Case locks and how to rekey them. Rekeying is the same for gas cap and seat lock cylinders.



Scan A.jpg


Scan B.jpg




:dance:dance:dance
 
Paul,

Just saw your pictures. One the pins is broken off the end of your lock cylinder (tumbler). You will need a new one:
51 25 1 455 109 LOCK CYLINDER WITH KEY $43.09

Once you get the new cylinder, you can rekey it to your ignition key before you install it. I will post the rekeying process as soon as I get my scanner working (later today or tomorrow).

You will need to clean out the recesses as mentioned in the previous post.

:dance:dance:dance

Thank for the information re: keying a new cylinder lock, Lee. :dance

Are you saying that once I open the gas cap, all that I will need will be a new lock cylinder and what I have will be back in operation? :scratch & :thumb
 
Are you saying that once I open the gas cap, all that I will need will be a new lock cylinder and what I have will be back in operation? :scratch & :thumb

Paul,

If you can clean up the two recesses that the two pins on the back of the cylinder engage in, and they aren't messed up, yes.

You should probably redisassemble the cap and make sure there is no binding in the locking assembly.




:dance:dance:dance
 
The K's Gas Cap Saga Continues

So the good news is that with the help of a friend's additional hands, thinner long nose pliers, combined with a wood working clamp (with plastic teeth) and a small screwdriver, the gas cap opened with no drilling. :dance :dance :dance

The downside :stick is the plastic insert that the tumblers turn, need replacing.

Now I have yet to go the bone yards, but I first called my local dealer where I was told the insert I need is not sold separately, only sold as part of the gas cap. Being curious, I asked how much the cap would be, :lol, and the parts manager said, nothing since BMW no longer sells that part. :banghead

With a holiday this weekend in Canada, it may be the first of the week (Tuesday) before my search resumes. I will find time this weekend to search Ebay to see what is available.

Who knows, maybe there's an old decrepit K100 gas tank, selling for next to nothing, that has a pristine gas cap attached to it, longing for a new home. :dunno

Worse case scenario, Monte's nail hole opener may be the final solution but I'll do a lot of searching before that alternative.

I better take the R out on the weekend to empty it's gas tank as I was asked to have it low on fuel on Tuesday morning when it goes in to have the Ohlins rebuilt. I do have two very large jerry cans but, they presently are filled with the K's petrol. :lol

Since the K's gas tank is off, and although for the most part, heat has not been a problem with this bike, this seems like a good time to make and install a "Johnny Blanket" under the tank/seating area.
 
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