Honda BF40A Sn BAYL 2000515 will not idle smooth

[waldo753]

kind of back pressure
, put your engine ;s lower unit in big bucket with full of water..
i hope it helps..
thanks
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BF40A Sn BAYL-2000515
Had some bad gas so I cleaned the carbs and replaced main jet #92 99101-ZV5-0920
as well as jet set 16150-ZV3-000 and seals and gaskets.
I don't know if my BF 40A sn BAYL-2000515 wants an initial 1 5/8 turn out on the new replaced pilot screws or 2 1/4.
The service manual seems to indicate BAYE and subsequent want 1 5/8 turn out.
It will not idle except with about 1/4 choke.
Carbs were balanced but the idle circuit must be clogged?
If i close the choke it will not idle (it dies).
I can close the pilot screws (fuel mixture) on each carb and it doesn't seem to make any difference.

 

[Mc Tool]

Sure does sound like an idle circuit issue

 

[waldo753]

BF40A Sn BAYL-2000515
Had some bad gas so I cleaned the carbs and replaced main jet #92 99101-ZV5-0920
as well as jet set 16150-ZV3-000 and seals and gaskets.
I don't know if my BF 40A sn BAYL-2000515 wants an initial 1 5/8 turn out on the new replaced pilot screws or 2 1/4.
The service manual seems to indicate BAYE and subsequent want 1 5/8 turn out.
It will not idle except with about 1/4 choke.
Carbs were balanced but the idle circuit must be clogged?
If i close the choke it will not idle (it dies).
I can close the pilot screws (fuel mixture) on each carb and it doesn't seem to make any difference.

I.will add the bottom carb idle is all the way tightened and still idles too

BF40A Sn BAYL-2000515
Had some bad gas so I cleaned the carbs and replaced main jet #92 99101-ZV5-0920
as well as jet set 16150-ZV3-000 and seals and gaskets.
I don't know if my BF 40A sn BAYL-2000515 wants an initial 1 5/8 turn out on the new replaced pilot screws or 2 1/4.
The service manual seems to indicate BAYE and subsequent want 1 5/8 turn out.
It will not idle except with about 1/4 choke.
Carbs were balanced but the idle circuit must be clogged?
If i close the choke it will not idle (it dies).
I can close the pilot screws (fuel mixture) on each carb and it doesn't seem to

Sure does sound like an idle circuit issue

Recently I had a full leak out the small silver choke cover on the side of the carb. I read this leak could be from a clogged main jet. Looks like I'm taking the carbs apart again.
I ordered another fuel water separator, hose and pick up tube. I'm going to try to clean the tank through the pick up tube.

 

[MattFL]

I have the 50HP version of that motor, bought it new in 99'. Take the carbs apart. If you've got the EPA fuel screws that can only turn 1/8 turn, break off the heads, use an extractor to take them out and replace them with proper adjustable screws. The part numbers are on here somewhere (order new parts before removing the old ones). If you have an ultrasonic cleaner, give the carbs a good soak in there. Then put carb cleaner and compressed air through every hole in the carburetor. Wear goggles, some will come back at you. When you hit the idle circuit, it will spray out through a bunch of tiny holes inside the carburetor throat, make sure those are clean. Once you get the carb really clean, it should work properly. Make sure you have no air leaks, use new gaskets and o-rings. Take a guess at balancing the carbs, you'll need to get the idle circuits in the carbs working properly before you can get a proper balance.

 

[waldo753]

The carbs were solvent cleaned (don't have an ultrasonic cleaner) twice. I will take them apart again and this time use a remote tank to get it running while I take steps to clean the on board tank since it must be getting dirt from the built in tank.
I have replaced the jets gaskets and orings last cleaning and I ordered another set of orings for this cleaning.
I also ordered 3 carb covers (part 18) since the bottom carb was leaking when I squeezed the primer bulb...which I read can be caused by a clogged main jet.
I think the carb cover seals is just a press in fit. I tapped the carb cover in and the leak quit so not sure I should replace them.
I will check out the gaskets and isolators when I disassemble them....or should I replace the gaskets even if they look okay?

My local Honda dealer doesn't work Carburated motors anymore. So I'm learning quick.