I had a similar problem. The lock seemed quite stiff for a while, then it went loose and just wouldn't work. It was really tricky getting the seat off, and after dismantling the lock I could see that the shaft connecting the bit where you put your key, to the business end which operates the latch - had worn out the notch it connects to on the latch. I was unable to find a replacement or do a decent repair, so I did a "temporary" repair which actually seems to have lasted OK. In addition because I didn't want to get stuck again, I tied a wire to the latch and ran it outside the framework so that if the lock fails again I can still remove the seat by pulling the wire. Dave
After reading the post below called Seat Lock-Seizing, Donna's 97F650ST lock gave us trouble getting the key in. Then it worked. I got details from David Elliott on how he rigged a wire to work the lock if the key quit working. I modified his fix by using a small wire tie around the latch, then looping a longer wire tie and letting it hang just outside the coolant tank. So, if the lock quits working, we can still get the seat off without much hassle. I'm just wondering how many others had the seat latch lock quit working on them. A couple answered the prev. post, anyone else? I went ahead and fixed up my 99 F650 the same way, even though no trouble yet. Dave #888
My '97 F650 experienced seat lock stiffness and difficulties at around 20,000 miles. I sprayed in a load of WD40 and worked it around really well with the key. That fixed it. At 25,000 miles the lock is still working fine, but I'm starting to feel a need to spray again as preventive maintenance. Brian 1025
I've just noticed it recently, but I attributed it to the crappy seat latch on the bottom of my Corbin. Going to have to see if the problem exists when I use the stock seat pan. Mark #403.
The seat lock on my 99 starting refusing to let go of the key about a month ago. The last couple of times I've taken the seat off I've had to wrestle with it to get the key back out. I haven't tried to fix it yet but it is interesting that others are having the same problem. It appears to be a very poor quality piece. I think I'll try the WD 40 solution. Mark #968
WD40 is not the best solution, because over time it attracts grit and grime, gumming up the locks. Look for dry spray graphite lubricant especially made for locks. It's pretty cheap and a small can should last you a lifetime. Mason #631
My seat lock seems to have gone south. The red bit is still there, but the key simply won't go in more than half way, as if the thing had disintegrated internally. Problems with both locks being sticky, I've had good luck with "Tri-Flow" lubricant recommended by a locksmith. David #476
Mine
did the same thing. I drilled the tumblers out of the lock with successively
larger drill bits until I could get the lock to turn with a medium sized
screwdriver. I found that I could still use the key once I got the tumblers
out. It was replaced under warranty on the last possible day.
You can order a key-matched lock from the dealer if you have the key
code. You have to buy the entire lock/latch assembly. It is part number
51-25-2-346-372, item number three in parts diagram number 51_0172. Make SURE
you have your key code when you order. There are only two screws that hold in
the lock and it is simple to replace. USE LOCTITE on the screws. Flash #412
Classic Seat Lock
Classic Lock Numbers
Don't make this more difficult than it needs be. I recommend the "TriFlow" solution. When I purchased a used '97, both the ignition and seat locks were "difficult," especially the seat lock as my keying experience was similar. I used liberal doses of WD40 on both tumblers, with many keyings, and both locks opened up and became very smooth. Some folks will recommend against WD40 – "...it collects dust..." – but I've not found this to be the case. I've used WD40 in all of my home locks and all of my motorcycle locks with much success and no problems whatsoever. It's always taken years before a lock becomes "difficult" again, and then I just give it another spray of WD40. And, by the way, neither of the red tabs on the BMW has disintegrated. Brian S
Mine started yesterday to seize up. One day perfect, next day very sticky. Temporary solution was WD40, but that isn't a good lubricant (yikes, not meaning to start another WD40 war!). So tonight I'll take the whole thing as much apart as I can and grease it up properly. Aleksander
Same thing...lots of graphite to keep it working. Unfortunately, the *(&%^ dealer couldn't replicate the situation...so no warranty repair. Andy #618
One year ago mine stopped working. Replaced under warranty. Craig #325