How to key side cases locks to the ignition key

[greg]

While you can purchase an adjustable lock assembly for a top case which can be keyed to the ignition key, no such side case lock assembly is offered for sale by Yamaha. However, you can do it yourself fairly easily:
 
1. Purchase top case adjustable lock assembly part # 59C281C00000 (I purchased it from Canada since it is not available through Yamaha USA)
 
www.yamahagenuineparts.com
 
2. It comes with several numbered plastic bags of tumblers and a key chart used to take measurements from your ignition key.
 
3. This chart will work for the side case locks just like it does for the top case lock - you will need to remove the tumblers from those (push them out) and rekey with the numbered tumblers from the bags (there are several tumblers in each bag- enough for 3 locks).

[traceroz]

You can also do it for $0 with the existing lock wafers;
 
- Remove lock barrel
- Inset ignition key to barrel
- Note how wafers protrude
- Pull out wafers and swap around to get the best fit
- Remove wafers one-at-a-time and use a linisher/bench grinder to "tailor" each wafer
- With ignition key inserted, wafers should be level with, or slightly recessed,into profile of lock barrel
- Re-fit lock barrels

[steveb]

You can also do it for $0 with the existing lock wafers; 
- Remove lock barrel
- Inset ignition key to barrel
- Note how wafers protrude
- Pull out wafers and swap around to get the best fit
- Remove wafers one-at-a-time and use a linisher/bench grinder to "tailor" each wafer
- With ignition key inserted, wafers should be level with, or slightly recessed,into profile of lock barrel
- Re-fit lock barrels

While "greg"s method of rekeying these locks is the most elegant (and most correct), and the above from "traceroz" is also effective, I took a simpler approach.  After removing the lock barrel and inserting the ignition key into the barrel, I took my dremel tool with a small "grinder" attachment and simply ground each protruding wafer carefully down until it was flush with the surface of the lock barrel.  Not elegant but very effective!  It took me about 1 minute per lock.  Now each lock works perfectly with my ignition key (as well as the original key that came with the lock set) and still locks very securely. 
 
These locks are very simple.  If one or more wafers are protruding above the barrel, the lock will not turn within its housing.  If all of the wafers are at (or below) the barrel surface, it turns freely.  Even after the grinding there was plenty of wafer protrusion (after removing the key) to keep the lock from turning. 
 
If worried about your particular lock, try it on just one lock first.  You've still got two left for the saddlebags if you have any issues.