Outdoor Power Equipment, Small Engine, Lawn Mower Repairs, Troubleshooting and Safety
Disassembly, Cleaning and Repair of Briggs and Stratton Small Two-Piece Flo-jet Carburetor, Part 1
Briggs Carb Part Numbers 294311, 295607, 295609, 299201, 393753, 393895
used on selected Models 060301, 060302, 060303, 060306, 060311, 060312, 060313, 060316, 060331, 060332, 060333, 060336, 060351, 060352, 060353, 060356, 060392, 060396, 060401, 060402, 060403, 060406, 060411, 060412, 060416, 060431, 060432, 060433, 060436, 060451, 060452, 060453, 060456, 061301, 061302, 061303, 061306, 061311, 061312, 061316, 061331, 061332, 061333, 061336, 061351, 061352, 061353, 061356, 061392, 061396, 061401, 061402, 061403, 061406, 061411, 061412, 061413, 061416, 061431, 061432, 061433, 061436, 061451, 061452, 061453, 061456, 080301, 080302, 080303, 080306, 080311, 080312, 080313, 080316, 080331, 080332, 080333, 080336, 080351, 080352, 080353, 080356, 080392, 080396, 080401, 080402, 080403, 080406, 080411, 080412, 080413, 080416, 080431, 080432, 080433, 080436, 080451, 080452, 080453, 080456, 081301, 081302, 081303, 081306, 081311, 081312, 081313, 081316, 081331, 081332, 081333, 081336, 081351, 081352, 081353, 081356, 081392, 081396, 081401, 081402, 081403, 081406, 081411, 081412, 081413, 081416, 081431, 081432, 081433, 081436, 081451, 081452, 081453, 081456, 082331, 082332, 082351, 082352, 082432, 130412, 130432, 130732, 131431, 131432, 131436, 131437, 131451, 131452, 131492, 132412, 132431, 132432, 132436, 132437, 132452, 132492, 144401, 144402, 144411, 144431, 144432, 144451, 144452, 145401, 145402, 145431, 145432, 145451, 145452
- Quick notes:
- The preset (preliminary adjustment) for both low (idle) and high (main) mixture needles is 1-1/2 turns out from lightly seated.
- The main jet and the emulsion tube (#4) must be removed before the carb upper body can be separated from the lower body.
Disassembly, Cleaning and Repair of the Small Two-piece Flo-jet Carburetor shown here is mostly the same as the Medium Two-piece Flo-jet Carburetor and the Large Two-piece Flo-jet Carburetor. The upper body has the fuel inlet fitting, inlet needle and seat, float and throttle. The venturi is a separate part which fits into the lower body. The lower body is made up of the float bowl, main jet and choke. The emulsion tube threads into the lower body and crosses diagonally up into the upper body.
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- #1. Briggs Small Two-piece Flo-jet Carb
#1 shows the idle speed adjustment screw (yellow), the idle fuel mixture adjustment screw (white), the main fuel mixture adjustment screw (green), and the choke lever (pink).
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- #2. Idle mixture screw
The idle fuel screw (#2) meters fuel entering the carb throat while the throttle is near closed position (#3). The initial setting for the needle is 1-1/2 turns out (counter-clockwise) from lightly seated.
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- #3. Idle fuel discharge port
The idle fuel discharge port (#3, black) delivers fuel with the throttle near the closed position .
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- #4. Main needle assembly and emulsion tube
Deeper inside the same hole that held the main needle assembly is the emulsion tube (#4) that crosses diagonally up into the upper body (#5) just before the throttle plate.
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- #5. Earlier version with packing nut
An earlier version of the Small Two-piece Flo-jet carb used a packing nut and needle (#5).
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- #6. Emulsion tube enters upper body
The emulsion tube crosses upward digonally from the lower body through the venturi into the upper body. During reassembly be sure the tube enters the recess in the upper body as shown in #6 with the throttle plate and shaft removed. Note the location of the fuel delivery holes (white) within the venturi.
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- #7. Exploded view of main jet parts
The main needle, spring, washer and o-ring are assmbled in the order shown (#7).
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- #8. End view of emulsion tube
When removing the emulsion tube, be sure to use a screwdriver that snugly fits the slotted end of the tube (#8) since the tube is made of brass, a soft metal, and is easily stripped or damaged. If there is a build-up of gum or varnish, it may be necessary to soak the carb in cleaner prior to removal of the tube. When assembling, be sure to blow out any chips that may have been created.
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- #9. Emulsion tube fuel discharge holes
The emulsion tube (#9) has a number of holes along its length that must be clear in addition to the hole down the center (#8). This end of the center hole is the seat for the main fuel adjustment needle.
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- #10. Remove four screws
After the emulsion tube has been removed, the upper body can be separated from the lower body by removing four screws (#10). It may be necessary to use a utility knife to loosen the gasket from the lower body (the gasket stays with the upper body).
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- #11. Float should be parallel to body
Invert the upper body and check to see that the float rests parallel to the body (#11) and that the needle moves up and down freely with the float.
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- #12. Remove hinge pin
Slide the hinge pin out with pliers and lift away the float and inlet needle (#12).
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- #13. Clip holds needle to float
The inlet needle is attached to the float by a clip installed as shown (#13). Inspect the needle for damage or a groove worn into the viton rubber tip.
Continue to Small Two-Piece Flo-jet Carburetor, Part 2.