Couple more things....
Greg mentioned if you have to keep adjusting your clutch cable it may be fraying and so you might want to be ready to replace the cable. I would also like to add that if you have to keep adjusting your clutch cable you should also check the nut that holds the drive sprocket on the motor. If that nut works loose the whole clutch assembly will move inward a bit and thus require more movement of the bucking bar to release the clutch (more cable pull). You definitely don't want to ride with this nut loose, not even limp home.
I think you probably have yet to get it adjusted properly, rather than having to keep adjusting it, so the above may or may not apply, just things to keep in mind and check.
In general the factory routing of the clutch cable is horrible. The angle at which the cable leaves the mount on the motor heading toward the clutch arm is too sharp and causes LOTS of drag. That long spring on the cable isn't really there to return the lever to home position, the internal spring on the clutch will do that fine on its own, the only function I can see of this spring on the cable is that it kinda rounds out the cable route as it is compressed. I could feel the cable rubbing over the spring when I pulled the clutch, drove me nuts. I, like many others, have added a small pulley wheel on my clutch cable to make the route to the clutch arm smoother. I built mine myself, it sits under the carb in the same area of the factory cable routing, the wheel replaces the spring to give me perfect cable angle with no friction anywhere. Most others have routed the cable more outside away from the standard cable routing by screwing a plate with a roller in with one of the gear cover screws. Either way is fine, took me a while to get mine perfect, the other kind can be purchased as a kit I think....
Just wanted to pass that on, so you know the clutch cable setup is horse-shiest from the factory, and its not you. If you use the factory setup you need to lube the **** out of the cable and make the smoothest possible route for the cable, otherwise you will end up with a bigger left arm than right! LOL