Hello All, Got a ski rope caught in the starboard Impeller, couldn’t remove in the water, cut line, limped home on one engine And got the remaining fibers out while on the trailer. BUT, now the shaft guard (400 in the diagram) screws are loose and the guard is resting against the shaft. The screws won’t seem to tighten. From the diagram it looks like there are elastic hex nuts (420) above the guard plate. Any ideas on how to tighten???