Carburetor flooding intermittently

[stuartc44]

Hi all,
I recently bought a 2009 Honda BF5 which I was told had been serviced. It starts easily and ran fine in a tub at home so took the boat out on the norfolk broads for a trial. All was well for about 45 minutes and then the engine revs started dropping and then stopped. Removed the hood, nothing looked wrong at first so tried squeezing the priming bulb and fuel flowed from the top of the carb. After draining the carb managed to get going again, sqeezing the bulb then was firm. It did it twice more and seemed to happen when there were higher revs.
I stripped the carb, not what I would call dirty at all but cleaned through the fuel inlet / fuel valve port and fitted a new float valve, genuine Honda £29. Next trip she ran for about an hour and a half and it happened again.
I have ordered some new fuel line and a fuel filter, cleaned carb again and will try again hopefully mid week. I am guessing that dirt, maybe bits of fuel line breaking down is going into carb and stopping valve closing. The float seems to move freely and looks to be complete without holes etc. Would anyone have any ideas as to what else I should check?

Thanks in advance, Stuart.

 

[gordmac]

Would have thought new valve would cure it. You may be correct about debris but thought that would be obvious.

 

[stuartwineberg]

Did you bin all the fuel in the tank, rinse the tank and flush the system through with known clean filtered fuel. I had loads of issues like this on a small motor and it was tiny amounts of fine sediment in the tank stirred up on each fill. Indicative that it ran stationary in a tank but not on a moving boat.

 

[stuartc44]

I did dump the fuel and flush it through, the tank and fuel looked fine. I have now new pipes and an extra filter after the fuel pump, weather permitting will take it out this Sunday. I have half a tank of fuel at the moment so will try shaking / stirring it up soon after starting to see if it starts flooding.
Thanks.

 

[stuartc44]

So, took boat out on Sunday and engine ran for about 3 hours without flooding. I assume either carb wasn't cleaned properly or the filter is working, or a combination.
However now have air bubbles showing in fuel filter, may have been there previously just couldn't see them, but have ordered new fuel line any way and see if that cures it.