First, remove the wire retaining ring on the back of the clutch basket, that holds the starter ratchet gear onto the clutch basket. Remove the collar and the spring and set aside. Do ya have a dial caliper? measure the o.d. of the clutch basket where the ratchet gear rides, then measure the i.d. of the gear. Subtract that from the first measurement to see how much clearance you have. You shouldn't have any more than .002 or .003"difference. If there is excessive clearance, the gear can twist sideways and allow the teeth on the gear to unmesh with the teeth the basket, which in turn will cause the kicker to slip thru like it's doing now. Same goes for the kicker gear on it's shaft, it should be a snug fit on it' s shaft/ Next remove the ratchet gear off the basket. Look at the teeth on the back of the basket and on the side of the ratchet it self. All the teeth should have sharp 90º edges where the mesh with either other.
Take some pics and post them