turned on boat this morning and i heard a clunk right as it cranked and it continued with the engine. its hard to hear at a low idle but its there in neutral as well as forward. didnt try reverse. it gets louder with rpm. it didnt sound like it was the engine so i took the outdrive off and gimbal and ujoints seem okay. nothing obvious by looking. any ideas what could be clunking. it was pretty loud and seemed very problematic i wouldnt not operate boat as such i could feel the vibration aswell in steering wheel when trying to get over 2k rpm the clunk would get bad ? any help appreciated