On my 1986 K100RS the helmet lock won't open, the U hook just stays trapped in.

The key just doesn't turn right, it only stays Left or Upright position. I've tried by pushing in, wiggling, etc but nothing.
(The seat lock mechanism works fine though)

I've read the great post by Sidecar Paul (How-To link), dismounted the item and put grease but nothing changed.

I've opened it, it seems okay, put some WD40, grease, etc but nothing to do about moving to position "2", it just won't turn.

Key in position "0":


Key in position "1":

Hi, maybe a silly question but are you using the wright key, maybe in the past they put a other ignitionswitch in.


grtz.

dutchie wrote:Hi, maybe a silly question but are you using the wright key, maybe in the past they put a other ignitionswitch in.

Yes I think I do because it turns on "1" position with no problem

Hi,
I've been looking at your post for a couple of days now and I can't see what could be causing the problem.
It seems to be somewhere in the lock barrel, so I can only suggest pulling the barrel from it's housing and checking for any obstruction. Maybe that little index plunger isn't fitted correctly (but I can't remember where it actually fits ).

Sorry I can't be more helpful.

Paul.

A couple of months back I serviced this lock. Neither seat nor helmet function worked. I got the seat lock to work but can't get the helmet hook to open at all. I have an accessories key which gets the seat locked but my ignition key doesn't work at all here.
I came to the same conclusion as dutchie that I may have the wrong key for this. I can't see any great wear or damage in the mechanism, it's now clean and lubed... it should work.

It might be worth having a look at this link if you haven't messed with these locks before and remove the barrel then check with your ignition key if any of the "tangs/wafers" protrude. If any of them (other than the rear most retaining tang) are protruding at all it could be the reason for your trouble.

I redid my second hand seat lock using this method a few months ago. I've also got touring panniers and city panniers that I have modified the locks in this way so that the ignition key from either of my K bikes works in both sets of panniers.

Good luck.

That's very hand information Gaz. Thanks for the link.
Cheers

That's very interesting Gaz, thank you very much.

Now I'll have to take it down for the third time (and last, whatever it is)

Just couldn't get the tumblr out its cylinder, "to depress the retainer tang and remove the lock core" as described on http://www.motobrick.com/index.php?topic=494.0

The lock barrel in these seat locks can only be removed when the mechanism is in its centre position.

I faced this issue when doing mine. See here for how I got around it.

Patience was the key.  

Thank you Gaz, I read that, I share the feeling (and kind of swearing too)

I don't have a proper lock pick though, I am not sure I've understood what exactly is the right movement to apply as I see no tiny hole but just a flat little piece of metal (brass?)
Shoud I try to enter with my pointy whatever between that and the cylinder wall? (where arrrow points in pic above)

Not sure if this thread has been shown from Frankenduck.

HERE

Should be all you need to understand the process.

Good luck

The retaining tang (the little flat piece of brass) needs to be pushed down in a radial direction, that is in toward the centre of the circle that is the barrel with your pointy tool.
Once it is down flush with the circumference of the barrel you should be able to withdraw the barrel out of the housing. Maybe having a key in the lock will give you something to grip onto while trying to withdraw the barrel.

Cheers

Excellent description fior the movement Gaz!

I just popped out in an eye blink with a cutter blade (strongly recommended) but when I had the trumbler in my hand all the flags went down by just holding it and also that tiny pin popped out, there is a spring where I suppose it should stay.

All flags down, unknown pin, key wont turn anywhere, big trouble now 
UPDATE: actually the retainer tang was not down, it was just broken and the tiny piece of metal is now apart

Ok I let it go, I put a little blade that stops the tumbler when pulling the key, the primary flag has gone into pieces so there'd be no way to stop it. Kind of a ghetto fix but better than having it locking your seat forever.

In case it's possible to adjust a second hand tumbler to my keys I'll do the substition.

Glad you have got the barrel out. Good luck with finding the small spring for the indexing pin.
I have seen an internet description, maybe Utube, of changing the wafers/tumblers and am sure they can be purchased and changed out so don't give up yet.

More info on these UTube videos

Video 1

Video 2

If I can find where the wafers are available I'll post.

Cheers.

I've got myself a second hand lock but it's in position 1 (left) and no key is available.

Is there any way to get the lock cylinder off to start the "rekeying" ?

I've pushed the tang in but still wont pop ...

JMHO but the helmet lock on K bikes is a pretty worthless design. I usually just take my helmet with with me but if I need to lock it up I use a lock like this:

duck wrote:JMHO but the helmet lock on K bikes is a pretty worthless design. I usually just take my helmet with with me but if I need to lock it up I use a lock like this:

Totally agree Duck, I'm going to use a cable lock too but it's just that all-working-as-first-day bug that won't let me go...

sobonatovada wrote:

duck wrote:JMHO but the helmet lock on K bikes is a pretty worthless design. I usually just take my helmet with with me but if I need to lock it up I use a lock like this:

Totally agree Duck, I'm going to use a cable lock too but it's just that all-working-as-first-day bug that won't let me go...

Yeah, I understand.

Maybe it's because I mostly ride in rural areas, but I just hang my helmet on the ABS bleeder.  No problems so far.

When I managed to get my seat lock to turn from the left (anticlockwise) position to the centre position so I could remove the barrel I did it using a miniature hacksaw blade ground down to something like this

I inserted this tool into the lock with the flat side facing the way the flat side of the BMW key would be and while applying pressure in a clockwise direction I dragged the tool out of the slot (I've read that locksmiths call this raking). Repeat, repeat, repeat ...................., wriggle the tool, swear, get another beer,  then continue. Mine only took several hours.

I'm sure you get the idea. Good luck.

I had this problem, and a squirt of ACF50 did the trick, and the barrel popped out! hope it works for others too.
Regards, Martin

I had this problem, and a squirt of ACF50 did the trick, and the barrel popped out! hope it works for others too.
Regards, Martin