Have an 08 big foot Honda outboard with a real bad problem. It will run ALL day long at speed when I don't exceed 5000 rpm (the tach goes to 7000) I mean I have driven for 1 1/2 hours straight at 5000 rpm and no problems what so ever. When I push it above 5000 (doesn't matter what number it is 5500 6300 etc etc) the engine will randomly drop in rpm and then immediately go back to normal. It will do this continually until I back it down to 5000 rpm then no issue what so ever. Bump it back up then the mess begins again. Thought it might be water in the fuel but then it should be doing that ALL the time no matter the rpm. It is really bad because I am missing about 5-8 mph (It's a 26ft pontoon) and it is really dangerous because the boat basically stalls for a micro second and you are thrown forward. It feels like a stall or hesitation but it ONLY does it above 5000 rpm. Any thoughts or ideas?