first your lock nut is backwards on your prop shaft, some adapters dont need a lock nut, they serve the same pourpose yours doesnt look like it though. first back plate ,prop,washer,main nut, lock nut, then adapter. if all this fits inside your spinner check the attachment screw some will be a little long sometimes .if it is then go to ACE hardware and get a shorter one simple. they usually have a good selection of cap head screws just bring your adapter nut and screw to check for proper threads. the lock nut should have the wedge portion twards the propeller if your adapter has this wedge you shouldn't need the lock nut. on four strokes make sure the nuts are tight they can loosen up sometimes