The motor started making a banging noise when I came off plane.I thought a rod or wrist pin had let go but it was not missing. Idled back to the dock and ran it at the dock,in and out of gear and the noise cleared. Ran it all over the next day with no problems. Banging noise started again the next day. Motor seemed tight.Pumping water ok but the top of the flywheel was hot. The block was not. Any ideas anyone?