not sure if the 85/86 is the same but the hub bolt is like a 27mm if i remember correctly. either get a gear jammer or use a coin to keep the motor from turning over while you take apart/reassemble every thing. be careful with the clutch spring bolts they like to break off in the hub if you give them just a little to much tension. if you don't have a clutch holder you will need to get one. other than that it's really not to bad of a project.