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

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?




ADD ON: This problem is very random in nature. I have gone flat out for 5-6 minutes and then it will start happening. Back off the throttle to under 5000 rpm and bam it WILL NOT HAPPEN. Only over 5000. (or 5000 on my tach) That being said you are not going to go flat out or even near the top due to safety issues for the passengers being thrown around

You could, very well, have the same problem as Captjohn.

The following is one of the posts from the Captjohn problem....

If your engine frame serial number falls between BBCJ-1000001 ~ 1012697, the fuel pump has been modified to correct just such a situation. If this happens to you and squeezing the fuel bulb keeps the engine running smoothly, that is the problem.

It should still be covered under warranty if you are in the USA. You should have a 5 year warranty on the motor unless it is commercially used. I am not sure how it might be covered elsewhere in the world.

The way to tell which one you have by looking at the low pressure pump....on the top rear port side of the engine. If the hose coming from the lower pressure filter goes to the upper nipple on the pump, then it is the old pump.
If the hose goes to the lower nipple, then it is the updated pump

If you have the older version fuel pump, when you are out, when it fails, squeeze the fuel bulb and see if the motor smooths out. Then it is probably the pump.

Depending on the hours that are on your motor, you should at least change the high and low pressure fuel filters. You should also drain the vapor separator into a glass jar, just to double check that there is no water in the system.

You should not jump into something that will cost a lot of money, if the problem can be solved with some simple maintenance items.

Mike