Honda BF 30hp 'flat spot'

Hi..

Recently bought an old Bonwito With boat that came with a Honda 30hp outboard 2005/6. She is tiller operated and pull start. As the seller was known to me ,i know the engine has very little use over the years and looks absolutely as new.

After restoring the boat i have now used them together a few times and whilst they are a good combo and fast, and engine starts easy, and is very quiet. There is only what i can describe as a flat spot half throttle.
If i just gradually increase the throttle as she reaches halfway she starts to struggle and if you aren't quick and wind the throttle up quick enough, the engine will stall.Happens at the same spot everytime

Anybody experienced the same problem and/ or, know how to resolve this problem..??

Thanks in advance

Shaun

I recommend you to remove the carburators and clean them. I expect a problem with one of the three carburators, or the accelleration system. Please check it carefully. The reason could be the very little use in the past 6/7 years.

Thanks Lenard...Offshore at the mo, but will check the carbs when i get home.

The engine certainly has had very little use, but the previous owner did say that when he first bought it he had a lot of problems with fuel and it was only when he went to a higher grade/octane that it cured this problem.
Whilst this occurred a few years ago, could my current problem be a 'hangover' from the fuel issue?..and would i be better using premium grade petrol ??

You do not need any premium gasoline, just fresh and clean gasoline. This kind of engines are consuming so little fuel per carburator that the quality of fuel as well as the cleanless of the carburators (orfices) is very very critical important!