I just today was tinkering on a friends Ryobi with the exact same problem, with no help from the internet, I then examined the end of the clutch shaft to see what type of attachment it had. According to the network, it was supposed to be a Torx screw, but under closer examination, it was a 9/32 allen wrench. I took the original spark plug out and inserted an old snowmobile plug into its place since it is a fair bit longer, I knew the piston would hit it and stop. I put firm pressure on the allen wrench to keep it from slipping, and turned it counter clockwise..Whala!! it came off. I then proceeded to remove each counter weight with a pair of channel lock pliers. The rest was easy,but I did find that the plastic bushing was wearing thin and was partly broken. I just scraped the old bushing out, and cleaned the rest of the parts. There is a metal washer at the bottom which holds the coil spring,when removed, it was rusty so I just steel wooled it. After cleaning I used a little vaseline to the plastic surfaces which turn on themselves, Undid the rope from the handle to recoil the tension on the spring,screwed the plate back in place to hold the coil, and retie the rope back onto the handle.Everything else went back in reverse order, but I put a dab of locktight onto the top counter weight as it looked that it was there from factory.And by golly gee wiz, the damn thing worked. Hope this answers all your questions.
Jim the backyard mechanic., September 2008
