08 bf90 hp random drops in rpm when running above 5k rpm

[g8tors09]

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?

 

[Packard8]

Re: 08 bf90 hp random drops in rpm when running above 5k rpm

Just a guess, but it sounds like an ignition issue....sometimes weak coils or a faulty CDI will act up at higher RPM's. Or could be it is hitting the rev limiter? I suspect it will take a shop with advanced diagnostic equipment to find the gremlin.

 

[Hardley Davidson]

what was the problem ?

 

[GA_Boater]

Hardley - Welcome aboard. This thread is inactive and the starter made one post and disappeared getting close to two years ago. You won't be getting an answer. Look at the Help Tips on top of the page and start a new topic with your questions. Thanks.