no start starter

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.

From what you are telling us I don’t think you have a bad starter, so please do these checks first. Start by checking the battery voltage. If it is too low or you have a bad or loose connection (positive at the battery or solenoid and negative at the battery or chassis), it will have the same results. You need a minimum of 11.5VDC to spin a cold engine. Bad connections will result in higher vol age needed. Please do not go rapping on the starter, as you will crack the magnets and will be replacing the starter, when it wasn’t needed. Report back what you find and include engine model and spec numbers.