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Old 26 September 2011, 15:16   #1
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BF50 stalls

Hi,

a friend of mine has a 2006 Honda BF50 which stalls when putting the throtle to wide-open starting from being neutral.
Looking at the prime bulb, it is like not having gas at all in it. If we throtle up in small steps the outboard runs nice. I think the problem is on the lower revs.

Can you help me diagnose possible causes? Perhaps the carbs not being synced?

Regards,
Luis
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Old 26 September 2011, 17:56   #2
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If the primer bulb is soft I'd say the problem is before the carbs so I'd check:

- air vent on tank
- fuel pick up is not blocked
- primer bulb is working correctly
- fuel line has not disintegrated internally
- fuel filters are not blocked
- fuel pump diaphram is intact.

But I am not an engine expert so someone else may have more specific/better advice.
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Old 26 September 2011, 18:01   #3
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I had EXACTLY the same problem with an Evinrude, it was due to flooded carb.

BUt Could be fuel pump, see if by pumping the fuel (using prim. Bulb) it gets better or not?

Also check all spark plugs and make sure the lead is connected as otherwise you are running your engine with not all cylinders...
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Old 26 September 2011, 18:07   #4
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Quote:
Originally Posted by Vandad View Post
I had EXACTLY the same problem with an Evinrude, it was due to flooded carb.

BUt Could be fuel pump, see if by pumping the fuel (using prim. Bulb) it gets better or not?

Also check all spark plugs and make sure the lead is connected as otherwise you are running your engine with not all cylinders...
But why was the carb flooded??? Lack of air?
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Old 26 September 2011, 18:26   #5
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Quote:
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But why was the carb flooded??? Lack of air?
Choke sticking I would imagine.
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Old 26 September 2011, 18:29   #6
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Choke sticking I would imagine.
But if the choke was sticking, wouldn't it give problems in the high revs too?
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Old 26 September 2011, 18:35   #7
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The problem was with the float and needle,

Yes, if choke sticks, it will cause too much fuel into one cylinder which could potentially make the spark plug "wet" so it won't spark.

With these problems you should do a proper diagnosis step by step, do some research on the net and check the whole system, you sometimes find things which need fixing but are not the main culprits!

Do Check your Fuel Tank, Fuel Line, and Prim Bulb, if old then change them,

Watch the fuel filter and first of all make sure it is clean, then see if you can see the fuel coming into it (from fuel pump) continuously at both low and high revs

Check ALL spark Plugs

Check ALL Spark Plug Cables and Make sure you have Spark.

Do a compression test at the end....
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Old 26 September 2011, 18:54   #8
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But if the choke was sticking, wouldn't it give problems in the high revs too?
Not stuck fast, it just lags the throttle response. So when you suddenly go WOT its flooding. If you slowing increase throttle the sticky choke gradually opens.

Needles get junk in them and floats can stick too.

I would just start by:
checking tank vent (easy)
replacing fuel filters (easy)
checking all plugs and wires (easy)
rebuilding the carb (bigger pain)
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Old 27 September 2011, 10:22   #9
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Hi,

updated information. Carbs cleaned and synced. Thermostat wasn't very good but is already repaired. The problem persists.

The spark plugs and fuel filter were also changed.

Could it be the electrical??? What should we test first place?

Regards,
Luis
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Old 27 September 2011, 17:03   #10
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Hi to all,

problem solved. It was the cam belt that was not installed within the marks and had some lag on it also.

Thanks to all.

Regards,
Luis
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