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BC Boat Guy
BC Boat Guy, Marine Trades Instructor
Category: Boat
Satisfied Customers: 94
Experience:  Marine TQ, Commercial Transport IP, Master Technician, Instructor, 25 years experience
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Honda outboard motor BF 75

Customer Question

Outboard motor honda BF75. Motor start when spray starting flued then stop. I took apart the carburator and clean. I remove carburator drain screw and see that fuel flow rfeely. If the motor start for a moment, it is mean that spark plugs is OK.
Tell me, what should I do.

Thank you
Submitted: 9 years ago.
Category: Boat
Expert:  BC Boat Guy replied 9 years ago.

Hi,

It can be very bad for the engine to use starting fluid as it is very volatile and also removes the lubricating oil from the cylinders. If you use a small squirt bottle with mixed gas it will still serve as a testing tool but is better for your engine.

Now, on with your problem. Did this problem start suddenly while in use or did it happen after the engine was in storage for the offseason?

Please let me know that info and anything else you can think of and I will try to direct you to the problem.

Thanks, Matt

Customer: replied 9 years ago.
Hi:

The motor was in storage for a off season.
Expert:  BC Boat Guy replied 9 years ago.

Ok, the fact that you have fuel getting to the carburetor and flowing out the drain is good. But quite often, even after cleaning, the jets and passages that actually deliver the fuel to the venturi can remain blocked with what we call "varnish". When untreated fuel evaporates in storage it leaves this gummy residue.

Remember that the high and low speed passages in the carb a very small. The high speed jet is also located right in the bottom of the float bowl where all of the contaminants will eventually end up.

I suggest you locate the high speed jet, remove it, and examine it very closely to make sure it is not restricted. Be careful if you have to use any picks or hard tools to unblock the passage that you don't damage the size or shape of the opening as even small changes can affect engine performance.

Good luck and let me know if this does not solve your problem.

Matt

 

BC Boat Guy and 2 other Boat Specialists are ready to help you
Customer: replied 9 years ago.
Do you mean Main nozzle? I know Main Jet which located on the top of Main nozzle and Main nozzle have a Upper and lower opening which I cleaned and can see through.

Thank you
Expert:  BC Boat Guy replied 9 years ago.

In my terminology, the main nozzle is the pipe which lifts the fuel and delivers it right into the throat of the carb. The main jet is mounted at the bottom of the nozzle, or quite often in the float bowl itself. Access to it is possibly through the bowl drain screw. The passage way on a main jet will be in the .020 - .030" range. Try to visualize the path that fuel will have to take to get from the fuel bowl to the nozzle in the venturi. The jet is the first thing that fuel will have to pass through.

Hope this helps, Matt

Customer: replied 9 years ago.
HI:

I did clean the jet, it was cloged, but after a cleaning the jet I even could not start the motor with a starting fluid as I did before.

Thank you.
Expert:  BC Boat Guy replied 9 years ago.

Lets try a test.

Make up a small plastic bottle that you can fill with gas. It has to be something with a squirt lid or a small hole that you can meter small amounts of fuel. If you clean out a small pop bottle an then drill a 1/16" hole in the lid that would work good.

If you use this, and experiment a little bit with the amount of fuel you are putting in, you should actually be able to keep the engine running as long as you keep adding fuel.

If this is the case, and the carb float bowl has fuel in it, then there has to be blockages in the carb still.

Please let me know what happens with this test.

Matt

Customer: replied 9 years ago.
it does work on the fuel which left in the carburatos. As soon as I pump the buld I overflow the carb and motor does not started.
I stink I need to set the float level in the carburator. Whot do you think?

Thank you
Expert:  BC Boat Guy replied 9 years ago.

If the carburetor is overflowing when you squeeze the primer bulb, then the needle and seat in the carb is not working correctly. All of what you descibe points to fuel that has gone bad in storage - there are products to add to the fuel in the fall that will prevent this from happening again.

As for float level, if you haven't changed it, it won't have changed while in storage. The carb needs to come apart again, thorough cleaning, and have a kit put into it because the needle and seat are either stuck open or not sealing from what you describe. The float level should then be checked anyway when you replace these components.

BC Boat Guy Matt

Customer: replied 9 years ago.
Hi:

What kind a kit do I need to put into carburator?
Where can I get it. Is a kit have a gaskets and needle?

Thank you
Expert:  BC Boat Guy replied 9 years ago.
A basic carb kit will have all the parts you need, including needle and seat. I recommend buying the brand name Honda parts from a Honda marine dealer.
Customer: replied 9 years ago.
Hi:

I think ruber gasket which separated two parts of carburator is not good. I called to dealers but they don not have the kit. They need to order. In a main time can I make my own gasket,or may be I can get some kind of seal? Thank you, XXXXX XXXXX appreciated you help.
Expert:  BC Boat Guy replied 9 years ago.

On parts that are related to the fuel system, I wouldn't recommend making anything to get by. The potential for leaks and fire hazard just isn't worth it.

Hopefully you are on the water soon. Nice talking to you and good luck.

Matt

Customer: replied 9 years ago.
Hi:

I manage to start the engine, Your help is really appreciated.

Thank you

Vlad Wood
Expert:  BC Boat Guy replied 9 years ago.

Hi Vlad,

Glad I could be helpful to you.

Happy Boating. Matt

Customer: replied 9 years ago.
Hi:

I,m sorry, but I do have the same probem. I put a new carburator kit. It was warking in my garage.
When I try to use on my boat, I could not started. Now my motor in the garrage and I need to fix it. When it start, it started and stop.
I chech fuel in carburator by draining fuel from floadit screw.
May be I need to adjust the idle or pilot screw.

Thank you
Expert:  BC Boat Guy replied 9 years ago.

Hi Vlad,

How did you adjust the pilot screw after rebuilding the carb? Is the idle speed just too low? When the engine is in the water, it requires more fuel to idle than when it is in the garage.

Matt

Customer: replied 9 years ago.
I return the engine back into garage.
When I adjust pilot screw it was originally three and a half turn, I put on thr same position.
The idle speed form the begining is high and than stop.

Thank you
Customer: replied 9 years ago.
HI:

I did not receive your response. Tell me what should I do to get your attention?
As told you before the motor from the beginnibng started and that sptops.
Expert:  BC Boat Guy replied 9 years ago.

Hi Vlad,

I have opted out of your question to allow other experts to perhaps provide you with additional information.

If no one repsonds, then I will continue to try to help you.

Customer: replied 9 years ago.
I've give you positive feed back.
As I told you before,The motor is started on the boat and stops. I brougt it back to the garage, clean one more time carburator but I still can not stat. Whei it cold it start for a second and stops.I try to adjust pilot and throttle screws. and I still can not start the motor.

Thanks

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