From past experience, whatever you use to flush out all the old tarry gunk, you can only ever do half a job with the barrel still attached to the bike. The ONLY way to sort a really poorly ignition switch is to flush it through with contact cleaner several times and invert the barrel to allow the cleaner, dissolved gunk and debris to run out. Of course in order to do this you will have to drill out the shear bolts and remove the barrel.

The trouble with flushing a lock out on the bike is that you tend to flush grit down to the bottom of the assembly. You can never be guaranteed to get it all out. Doing it insitu will improve things, but it's not the total solution.

Whichever method you use, make sure the internals are absolutely bone dry before applying any graphite powder.

As I've mentioned elsewhere, one of the best ways of keeping your ignition barrel operating smoothly long term is to cover the top with a rubber bung (sink plugs work well) whenever the bike is parked up outside. Also think about where you keep your key. Much of the dirt that accumulates inside ignition barrels is transferred to it unwittingly on the key from the crap in the pockets of your trousers/jacket!

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