5 h.p honda problem

[harbour]

Dear Sir. I have repaired lots of outboards in my years, however at the moment this 5 HP Honda has me beat.Run great last year, tried it this year, it starts great, however I can only get about half revs on the engine.Some times it will go to full revs but it struggles, then as if it is trying to die .It seems like a carburator problem as it will gain full revs on choke.I have checked the whole engine for problems, changed sparkling plug, had carburator ultra scan cleaned, but made no difference.Everything, fuel, spark ect on the engine is OK but I seem to be missing something. Any ideas will be greatly appreciated.

Thank you

Harbour

 

[zzzzz]

Re: 5 h.p honda problem

remove the carb and open it up...the emulsion tubes(main jet) are prone to cracking where it attaches to the top half of the carb...these cracks can be miniscule so shining a strong light through the tube can help you see them...cracks can cause a problem similar to yours

 

[harbour]

Re: 5 h.p honda problem

Thank you for your advice.tried what you said about carburator.I know it sounds quite silly but I am resonably sure carb is a good one, as I really scrutinised it.Really got me beat .Anything else I could possibly try.
Thank you
Harbour