I have a 78 45HP that I recently purchased with my boat. owner say that he was having trouble getting in reverse. I took boat out and noticed a lot of noise when shifting into reverse. and drives forward fine till you good to kick it in pass 1/2 throttle just spins, and have to bring down and will reengage again. I have lower drive apart, but do not know what to look for as far as worn gears/bearings. Any help would be apreciated. Thanks George