non bent good condition properly installed there is no reason they should scrape the flywheel or make any such noise. My advice is fix the water problem and or run your bilge more and install a new one. You leave your pumps or pump on auto? If it's not doing the job maybe install another pump closer and a little lower to the stern. I hate water in the bilge myself. Safety, yes can be an issue also. You might know about it but a friend or the next owner might not. We've all prolly ran without from time to time however likely for a short period of time. Just my personal opinion anyway.

as long as you know you keep your bilge clean i dont see a problem. if you have small tools, dropped parts, ropes, etc down there i would keep it installed so none of those parts get cought up in the flywheel. that being said i did not install mine back on the engine.

the auto bilge picks up down to below 1" sothat is ok. I plan on putting the guard back on and testing before I put the engine back in. Thanks, Chris