I have a problem. My petrol tank fuel cap will not unlock. My fuel is running low and; apart from taking it to a locksmith to drill out the lock barrel, I am stumped. And advice?

The only thing I can think of at the moment is that there may be some corrosion or a piece of dirt/ anything preventing the key going in far enough. Maybe a gentle tap with a hammer on the key to dislodge whatever it may be.

considering the upward facing lock opening ,which is I'm sure a trap for moisture , and given the age of these machines it would be expected to encounter some hindrance during the life of your K.
is there any merit in the thought of applying either WD40 or fine grade sewing machine oil to lubricate the lock. would this be of help on a regular basis?

this has been done before gunsports

have a "search" in the forum

but you can sometimes help by pushing down on the fuel cap , to relieve some tension on the cam that locks it closed
usually the little plastic recesses in the lock mechanism strip out ....usually from trying to go the wrong way .

but if the cylinder is not turning after the key is inserted ...get some wd 40 or something similar and flood that lock mechanism so that the wafers get flooded with something slippery ....leave it for a good while ( an hour or so ) so that it has time to dissolve the crud buildup

we often see that the cam operated pullback latch becomes restricted by some corrosion also .

...hope you get it solved as I cant think of where to get a new cap from ....other than something second hand ???

some have tried pushing the folded pin used on the "hinge" section at the rear out ....the tank does get in the way though

good luck !!

groverK wrote:considering the upward facing lock opening ,which is I'm sure a trap for moisture , and given the age of these machines it would be expected to encounter some hindrance during the life of your K.
is there any merit in the thought of applying either WD40 or fine grade sewing machine oil to lubricate the lock. would this be of help on a regular basis?

only if on regular basis ed ....
all those oils collect dirt and detritus like a magnet over time and as they dry out and coagulate ...dry and with graphite only is the recommended long term lubrication for just about any lock mechanism .
but the moving latch parts could always do with something slippery and non hardening
???

A soak in WD40 worked to free the cap on my RS (parked outside under a tarp for 5 years).

Al

Gunsports - sound like a problem I had last year too. However, you don't say what the symptoms are:

1. Key won't go into the lock fully? Probably crud build up in the lock, but bent/damaged key would have the same effect.
   
2. Key goes into lock, but lock will not turn? Probably corrosion of the dissimilar metals in the lock, and/or crud build up in the lock. A good soak with WD40 or other penetrating oil might get things moving again if you're lucky.
   
3. Key goes into the lock and turns, but filler cap will not unlock and release. Probable damage to the lock barrel locating pins or the plastic housing recesses that they go into - i.e. lock barrel turns with the key but does not turn the release mechanism.
   

I had the this problem last year, a few weeks of intermittent problems unlocking the filler cap (I wrongly assumed it was down to a worn key) so didn't do anything about it until predictably.... I was low on gas and cussing at the petrol station when I could open the filler cap at all. Luckily I had just enough in the tank to get me home on vapours.

The only way I could get the filler cap open was by breaking the hinge (I couldn't find anyway of accessing the hinge pin). Once the hinge was broken, the cap could be removed. The release mechanism is secured in the filler cap by 3 screws - removing these screws allows inspection of the lock mechanism. In my case, it was the alloy of the lock barrel that had cracked and no longer held one of the pins securely. Over time, this had worn the plastic housing too, with the net result that no matter had much I turned the key (or swore at it), the lock barrel no longer engaged with the filler cap release mechanism and it wouldn't release.

I got myself a replacement filler cap off fleabay (cost about £40 and wasn't in great condition - as shown below, but at least it worked - it also came with an ignition lock and helmet lock that I din't need, but used the same key) and it was easy enough to fit having removed the remains of the old filler cap from the fuel tank). While I was waiting the few days on the fleabay delivery, I was able to keep using the bike using good old duct tape to secure the hinge end of the filler cap - not pretty, not very secure, but functional!



Hope this helps.

Gunsports,
Some time ago Saxon7 posed the same question. I had a look at a cap and suggested drilling a hole in the cap and then using a screwdriver to push back the locking bar.



Saxon didn't try the idea, he found a key to open the tank, but it would be worth a try rather than destroying the hinge.

The hole could later be filled with a rubber grommet which could leave access to the locking bar should it happen again.

Good luck,
Paul.

Thanks for the advice. Used some silicon on the key a few times and managed to get the cap open. Still does not work perfectly, but at least well enough to fuel up. This weekend; will tear the whole thing down and soak it in WD40; then see if this does not fix it.

might be best to pull the lock cylinder and file off the excess on the wafers of the lock after trying a newly copied key  

unfortunately key profiles of the lock change overtime as they wear ( talking about the lock cylinder right now ) but it might be an idea to get a new key cut before hand using a standard nieman blank ...which  just might restore some worn out bits-profile  of the key itself before anything else ...

make sure it works well in all the other locks before proceeding with the wafer alteration ....just a suggestion