So, after flooding the lock on my new-to-me 82k mile '04 Wee with various slippery liquids and still having to jiggle the key to go anywhere, I decided that it was time to dismantle the lock and figure out why it's sticky turning on and nearly impossible to engage the column lock. The key works fine in the fuel cap and seat lock, however.
The "correct" way to fix this would be to replace the ignition lock or the wafers, but this method is free.
Tools: one "security" Torx T-40 bit. I got mine as part of a set for $9 at Harbor Freight. You'll also need a #2 Phillips screwdriver and something that can remove brass (sandpaper, file, Dremel, etc)
Time: 30 min, give or take.
First, you need to get the ignition lock off the upper triple clamp. The service manual says to remove the fuel tank first so you can get at the plug on the wiring harness. We're not replacing the switch, so we'll just take it off and work on it in place. Unscrew the two T-40 security screws from the bottom (they've got threadlocker, you'll need a ratchet) and the switch can be brought up and around:
Now, take out those two phillips screws holding the lock together. Take off the top, watch the shutter piece fall out, then lift out the lock cylinder. Here we go:
Hey, look. Brass wafers and a steel key
Small wonder these locks have a habit of being sticky when they get old. A wafer lock with the correct key in it should be a nice smooth cylinder. For some reason they went to the effort and expense to use an eight-pin lock, but they couldn't use steel wafers? (BMW bikes have a six-pin lock with steel guts and the one on my '98 works like new, as does my '98 KLR where they used brass keys) Here's what mine looked like:
Epic fail. I'm surprised I could even get the bike to turn on. Here's what it looks like in pieces:
Here's where you can check for random debris that might be causing your lock not to work right. Mine had none.
Note how each wafer has the hole in a slightly different place to fit the corresponding spot on the key. In theory we should replace these because they're worn and then the lock would work fine. Unfortunately, they're not numbered or marked in any way, so that's easier said than done. We'll mod them instead.
Put the wafers back in the cylinder. They do need to go in the right place, so I hope you kept them in order
What you want to do now is file those protruding wafer tops down so the cylinder is smooth with the key inserted. Making sure the key is fully inserted for the whole process
, sand, file or grind the wafers down so the whole assembly is nearly cylindrical. I used a sandpaper cylinder on a Dremel-type tool. It'll look like this when done:
Worth noting is that if you only have one or two wafers that are causing the lock not to work, you could remove the offending wafer and its spring instead.
Without the key, it looks like this now:
Note how these aren't sticking up quite as far as before, but there's still plenty of metal keeping the lock from turning without the key.
Put the cylinder in the lock and play with it to make sure it turns freely. If it doesn't, find where a wafer's still sticking up and fix it.
Put it all back together and enjoy not jiggling your ignition key when it's time to go to work. My column lock works now, and I'm pleasantly surprised to see that Suzuki made it difficult to turn past LOCK to P by mistake. Ask me about push-starting my old KZ750 after leaving the switch in P
Q: What if I get a new key cut from the key number?
A: The lock sticks because the brass wafers are worn. The steel key wears very little in comparison, so a new key won't fix the problem, though my less-used key took slightly less fighting than my well-used one. If you get a new key after doing this mod, it will still work--you haven't re-keyed the lock, just added a little bit of slop so the key will operate the badly-worn lock.
Q: Won't this make my bike easier to steal?
A: It does make the lock somewhat easier to pick, bump or use someone else's key in, but how many motorcycles are actually stolen by picking the ignition lock? I also like to park next to shiny Harleys or flashy sportbikes--at least in the USA, no one's going to steal a Strom with bumper stickers and faded Givi luggage when there's a Road King or Gixxer right there for the taking!
Q: Why not replace the lock cylinder?
A: A new lock cylinder is definitely the "correct" way to do it, but then you have to re-key your gas tank and seat lock (difficult to do at home unless you're a locksmith since the wafers don't have markings) or have two keys. FWIW, BMW numbers their wafers so if your ignition is keyed "231212" you can key any other BMW lock to match that one by putting the correct wafers in the cylinder--luggage keyed to the ignition key is a big selling point for ze Germans. If Suzuki wafers were numbered or somehow marked, you could just replace them with new ones of the correct number, but they're not.