I don't have the KLR documentation book on locks, however when my locksmith friend helped me out, he taught me how it was set up.
I don't remember the exact numbers, so don't quote me on this, but this is how it was set up on the 2008 stock.
If the ignition is a 6 pin lock, the key has 6 cuts.
The gas cap only requires the first 2 or 3 cuts to match, as it is only a 2 or 3 pin lock.
The helmet lock is a 4 or 5 pin lock, so that will require all but the very outer 1 or 2 cuts to match.
The key that matches the helmet lock will most likely be the original key to the bike, as I can't imagine that being changed.
Oh and make copies, lots of copies...I only know all of this because my key disappeared the night before I was supposed to leave on a two week trip. I am very fortunate to have an automotive locksmith friend.
Ridin an 08 and loving every second of it