Was riding with some friends at a local track this weekend and one of the guys pulled in my clutch lever on my 04 yz450 and was blown away on how stiff it was. I know the clutch is hard and have replaced the clutch cable, checked the routing, and nothing has helped. My arm gets tired very quick. One of the guys suggested the clutch springs had to be the culprit for how hard it was to pull. One guy suggested the basket was grooved but after riding it said the clutch was way too smooth for it to be grooved bad enough to make it that stiff. So if it has an aftermarket clutch with heaver springs how much harder are they than OEM on average? Can I put oem springs in it without any problems? If not can someone explain why? Thanks again, I am just tired of my left arm going away after the first 15 minutes of riding. And I thought it was just my weakness but everyone Saturday said they could not imagine trying to ride the bike for very long.