Honda BF8 o/b running baddly

[cameronke]

I have had 4 carefree years from by Honda BF 8 outboard untill the end of last year when it started to run poorly and die. The petrol tank was floating about in patrially flooded bilges so I assumed my petrol had become contaminated with water (sea).

I replaced the petrol and purged through the carb and that got me home.

However this year she wasn't performing too well: would die if asked to idle and die if fast throttle lever operated.

I stripped the carb and found some pale amber crystals in the float chamber. I am assuming that these somehow precipitated out the water/fuel mixture. Anyone any idea what this might be? Can anyone suggest a suitable solvent?

After cleaning the float bowl and its galleries the motor appeared to run better for a while but was soon back to poorly.

Really appreciate any input anyone may have

Regards
Cameron

 

[Cliveshep]

I don't know what your amber crystals are although I've seen them in my own engines in the past. You need to strip and thoroughly clean out everything, tank, filter, pump, lines and carb and blow the lot out with a proper air line, checking that all the carb jetways are also clear, not just the jets. Any tar residues can be cleaned with brake fluid (Lockheed or Girling type).

Fresh fuel should then sort it all out.

 

[VicS]

Re: Honda BF8 o/b running badly

I does seem likely that the problems are fuel related but checking the sparks and fitting new plugs is always an easy and wise first step.

No idea what the amber crystals would be. Salt crystals coloured with some ferric chloride ---at least if it was a steel tank that may have rusted a bit --- perhaps. If so warm water will dissolve them. Organic solvents won't.

Suggest you go through the fuel system again.
Make sure the tank is thoroughly cleaned and the fuel line flushed. Clean the fuel filter and make sure the fuel pump is also clean.
I think I'd strip and clean the carb again. Make doubly sure all the passages are clear. It may be necessary to extract blanking plugs and fit new ones. I'd poke a soft copper wire through all the jets to make absolutely sure they are clean. I have had to do that when water has got in to the fuel.

If you have not already it might be wise to fit a full carb overhaul kit if one is available. No idea what parts you'll get though.

 

[cliff]

Re: Honda BF8 o/b running badly

Had similar crystals to those you describe in a Yamaha carb. Carb cleaner or acetone dissolves them although in my case I found acetone worked faster.

Another "trick" is to remove the carb and place it in very hot (almost boiling) water for a while, giving it a good swill round, if the carb cleaner acetone does not work.
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Artificial Intelligence is no match for Natural Stupidity.

 

[Lakesailor]

Have you emptied the tank and checked for water again? Condensation can build up and even forecourts supply petrol with water in.
I got about half a pint of water from a standard OB tank after just 6 months.

 

[cameronke]

Many thanks for the ideas all!

It was a plastic tank so can probably rule out rust, will investigate further with all your suggestions in mind next weekend.

Regards
Cameron

 

[alahol2]

Just been through this with a yamaha carburettor. Make sure you find all the jets... mine had 3 separate jets, the main one, one at the bottom of a long tube, and another at the bottom of a long tube that was blocked off with a plug. A detailed exploded view is very helpful.