Dude, do not go buying a steel gear set just plain because you don't need it. Get you a steel spur gear to match your clutch bell if you want and forget it. It is probably stripping because the mesh was not set correctly. When you install the new gear, get a piece of printer paper and roll it between the gears while you press them together and tighten your engine bolts. Remove the paper and rotate the gears. They should be set so that they rotate without any binding or excessive amount of play. If you try another plastic gear, get you some Dupont teflon multi-use lubricant (dry lube) and give them a coat of that. That stuff is a dry lube that coats them with teflon after it dries. Bicycle racers use it on their chains because it does not attract dirt.