Actually, I have found that through this website you can get a service manual with the online version and it has an option for ordering parts, just about every piece of the motor.
http://www.google.com/search?client...gc.r_pw.&fp=6f6d84c58b469013&biw=1653&bih=936
Buy some new muffler bearings while you are at it.
http://www.google.com/search?client...gc.r_pw.&fp=6f6d84c58b469013&biw=1653&bih=936
Buy some new muffler bearings while you are at it.