One thing I found with the pre 08' KLR's is that there's a lot of heat that comes off the engine/radiator on the lower left side while riding. Enough to make life very uncomfortable and actually cause burns to your leg.
I have a set of mesh pants and I can't ride the KLR with them for very long. This is when I use a pair of tank panniers, I should add.. Can't vouch for riding without them, since I never take the panniers off..
Anyway, a few years ago I and Double A rode our KLR's to Lima, OH for the National BMW rally, leaving the BMW's at home, just to be different.. Anyway, I knew the weather was going to be hot and dry, so I wore my mesh pants. By the time I got halfway there, I had to ride with my left leg sticking out on the end of the peg. I actually got 1rst degree burns out of this, peeling the next day..
I ride my KLR with non-mesh pants from now on, saving the mesh pants for riding the other bikes.
The tank panniers may have something to do with this, as the bike actually runs cooler with them on. I think they may force more air through the radiator, but they also block air to my upper legs. The burn occurred below the panniers, and again, only on the left leg (same side as the radiator)..
Just something to think about..