Combustion Problem?

[km1125]

Does your float bowl look like the one in post #13?? Did you make SURE that passageway was CLEAR? You can try and spray something in one end and see if it comes out the other, but be careful because if it's plugged the spray might come right back into your face.

 

[Sea Rider]

Did you make SURE that passageway was CLEAR?

A bird has had to be nesting there for those wide fuel orifices to have gotten clogged, never seen such scenario....

Happy Boating​

 

[km1125]

A bird has had to be nesting there for those wide fuel orifices to have gotten clogged, never seen such scenario....

Happy Boating​

I can guarantee it happens. The whole passage was filled with hardened goo even though the bowl and the rest of the carb was clean. Tried soaking it a few times and the only way I got it clean was to run a flexible wire through it several times.

 

[Panhandle Nick]

Does your float bowl look like the one in post #13?? Did you make SURE that passageway was CLEAR? You can try and spray something in one end and see if it comes out the other, but be careful because if it's plugged the spray might come right back into your face.

My bowl looks very similar. I'm going after it tonight. I'm going to soak it and look again at the passages.

 

[MattFL]

A side note, make sure the bowl is actually filling with fuel.

 

[Panhandle Nick]

Yeah, I've confirmed the fuel pump works and the bowl is full, i checked the bowl by loosening the screw at the bowl. In an earlier post i indicated i can see fuel inject into the carb throat when the accelerator pump is moved with the throttled arm. At this point I've soaked the disassembled carb over night and cleaned again and re assembled. Shortly I'll install it and test.

 

[Panhandle Nick]

A side note, make sure the bowl is actually filling with fuel.

Hi Matt,
So it starts with starter fluid but won't idle or accelerate with giving gas. Or rather trying to accelerate the motor or rev the motor. I've had the carb apart 4 times now. Last time i soaked it overnight in carborator cleaner. I blew out every orifice and passage way i can see. And cleaned with small diameter file rods. If it kills it to give it gas what is a common carburetor problem with that symptom?

 

[MattFL]

If the slow speed circuits are plugged, then often you can keep it running with the choke and throttle. If you get it started with starting fluid, can you keep it running at all by giving it throttle plus the choke? If yes, then there's still something plugged up in the slow speed circuits somewhere. Does that carburetor have a fuel screw (adjustable mixture screw)? If yes, make sure it's not turned in all the way. If it is, turn it out 1.5-2 turns as an initial guess.

 

[Panhandle Nick]

If the slow speed circuits are plugged, then often you can keep it running with the choke and throttle. If you get it started with starting fluid, can you keep it running at all by giving it throttle plus the choke? If yes, then there's still something plugged up in the slow speed circuits somewhere. Does that carburetor have a fuel screw (adjustable mixture screw)? If yes, make sure it's not turned in all the way. If it is, turn it out 1.5-2 turns as an initial guess.

 

[Panhandle Nick]

Matt, would the screw be internal, or like a jet accesses from outside the carb. I don't see any idle or fuel mixture screws.

 

[Panhandle Nick]

If the slow speed circuits are plugged, then often you can keep it running with the choke and throttle. If you get it started with starting fluid, can you keep it running at all by giving it throttle plus the choke? If yes, then there's still something plugged up in the slow speed circuits somewhere. Does that carburetor have a fuel screw (adjustable mixture screw)? If yes, make sure it's not turned in all the way. If it is, turn it out 1.5-2 turns as an initial guess.

Ok yes, i just tried that and that works.

 

[Panhandle Nick]

I was able to start the motor and keep it running with it choked and using throttle. I don't have an issue adj screw on this carb. Does the low idle circuit use air to suck in fuel through the little tiny holes at the top of the barrel closest to the intake manifold. There are about 5 or 6 holes and they are like the size of a needle in diameter. Do you know, at idle, what position the butterfly valve is supposed to be in relation to these holes? Should the valve be open enough to expose all of the holes in the no throttle or idle position?

 

[km1125]

Typically the throttle butterfly would only show ONE of those holes when it is in the idle position. That one would be controlled by the idle mixture screw. You probably have one of those screws, but it's "hiding" under a brass cap that is put there so folks won't mess with the EPA setting for that screw.

 

[Panhandle Nick]

Typically the throttle butterfly would only show ONE of those holes when it is in the idle position. That one would be controlled by the idle mixture screw. You probably have one of those screws, but it's "hiding" under a brass cap that is put there so folks won't mess with the EPA setting for that screw.

Well if it's hiding, i doubt it moved and is probably not my problem. I just can't seem to find any blockage in the passage ways. So my idle throttle position is ok and not the problem. Is there any other reason a perfectly clean carb would be bahaving this way?

 

[MattFL]

Will it stay running with throttle but no choke? If yes, will it run at idle speed using the throttle to control it? I'm wondering if the idle is set too low.

 

[Panhandle Nick]

Will it stay running with throttle but no choke? If yes, will it run at idle speed using the throttle to control it? I'm wondering if the idle is set too low.

On this carb, how would i set the idle? Is it

 

[Panhandle Nick]

On this carb, how would i set the idle? Is it

Is it the screw that positions the throttle. The screw that touches the accelerator pump stem or shaft?

 

[pvanv]

Idle speed is set with the idle stop screw. But odds are the low speed circuit is still crudded up.

 

[Panhandle Nick]

Ok. If i use air and it gets through, and i use carb cleaner with the nice red tube directed into the passages and it comes out. What else could it be? Could there be a passage i missed? What enables idle? Is it the little holes at the top of the throat, dropping gas into the throat by air venturi? I know that passage is clean and clear.

 

[Panhandle Nick]

In this picture, in the small hole of the two, there's a slotted brass screw with a hole in the center. I can put a small round probe/ file, not using it as a file though, down into that hole until it bottoms out against something hard I just can't see in there. I can't turn it when I put a screwdriver to it and I don't want to force it. Maybe this is the fuel air mixture screw adjustment. When this is upside down this must be the only way that fuel can get up into the passages on the top of the carburetor. Because it is in the carburetor bowl or all the fuel is. Does anyone know if this is the low idle circuit.