I recently rode my mint condition 2002 KX500 that I set up with 13/52 gearing and Steahly flywheel weight. I also have a 2005 KTM 300EXC which I have been riding quite a bit since March. I rode the KTM on Saturday then switched to the KX500 on Sunday. Here is what I noticed.
Compared to the 300EXC, the KX feels like it refused to make tight turns, such as making 90 degree turns around trees in the woods. The KX feels like it was designed to go real fast in a relatively straight line, and that's most likely what the engineers actually had in mind.
The KX is much more stable than the EXC running fast through deep sand and sweeping turns with berms made of sand.
These two bikes are very differnt indeed.
The 13/52 gearing is a waste of time unless you're going to be running very slow through extremely tight woods. But I now feel that the KX does not belong in the tight woods, at least as long as I have the EXC available.
I have my KX jetted such that the engine either idles or accelerates very hard. There is no inbetween. So riding along I'm either coasting or rolling on a very small amount of throttle which causes powerful acceleration and small wheelies. This is not a good characteristic for tight woods riding for me.
The power output of the 300EXC is just right for maintaining traction. The KX running through the 13/52 gearing broke traction too often. There is so much rock hard thrust available at all times. The 300EXC has a little "give" to the engine so that as the tire grabs and slows the engine traction is maintained. The KX never gives in so the tire breaks loose.
I got about 18 MPG riding very easy. The 300EXC uses about the same amount of fuel.
Since I have the 300EXC I'm giving up on using the KX500 for Hare Scrambles. Instead, I'm going to use the KX as a dual sport bike. I fortunately have a license plate. The gearing will go back to 14/47. I'll add the lighting coil, headlight, tail light, etc... I think I'll have more fun riding on trails, traveling between small towns in rural Minnesota. With the license plate I can ride into town and buy gas, etc... The 300EXC will be my Hare Scramble race bike.
I had thought about making the KX into a Supermotard street bike, rather than a dual sport. I'll stick with the 90% dirt, 10% street dual sport plan. I now think that a 4-stroke engine would be better suited to a Supermotard street bike that would be ridden 90% street and 10% dirt.
