Hi. Got a kohler 15 hp. gravely, has served me very well. Went to change oil yesterday, pulled into shop and then shut off and had to move a little more. the starter stuck in the flywheel and wouldn't go down by itself. tapped on it, it returned and did the same thing. Took off opened it up, not a lo0t of dirt or black from brushes I assume. My question is, I don't know how to get the black plastic cap off and get to the clip. If the brushes are decent is the bendix the problem. thankyou in advance.