1983 Big red 200e starter engages but the engine will only turn over sometimes

[Honda Junki]

My starter engages everytime I push the button but like I said, the engine will not turn over everytime. (It also makes a bad grining noise when spinning over) I feel like the problem has to do with the starter gear that is attached to the crank inside the engine, whether the teeth are wore off the gear or its something else. If anyone has any ideas or input let me know please! Thanks