Sierra Needle & Seat Assembly 18-7057 for Tillotson AJ/CO/KA/KB/KC/KD/WB Carburetors, Chrysler/Force Outboard 120-135 HP

The Sierra 18-7057 Needle and Seat Assembly is a direct-fit fuel metering component for Tillotson AJ, CO, KA, KB, KC, KD, and WB Series carburetors used on Chrysler/Force outboard motors. This assembly controls the flow of fuel into the carburetor bowl, seating against the float-actuated needle to shut off fuel supply once the bowl reaches its proper level. A worn or pitted needle and seat is a common cause of flooding, hard starting, and rough idle, and replacing this wear part restores accurate fuel metering without the cost of a full carburetor rebuild or replacement.

Constructed of metal for durability against constant fuel contact, the 18-7057 has a bore size of 0.078 inch and is built to meet or exceed the specification of the original equipment part it replaces. It fits Chrysler/Force outboards rated at 120 HP (models 1208/1209HD, HE, HF, and HG) and 135 HP (models 1358HA, HB, and HC). Because carburetor needle and seat fitment is model-specific, confirm your outboard's model and carburetor series against the fitment listed below before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7057
• Compatible Carburetor Series: Tillotson AJ, CO, KA, KB, KC, KD, WB
• Bore Size: 0.078 inch
• Material: Metal
• Color: White
• Weight: 0.01 pounds
• UPC: 030999320940

Fitment

• Chrysler/Force Outboard, 120 HP, models 1208/1209HD, HE, HF, HG
• Chrysler/Force Outboard, 135 HP, models 1358HA, HB, HC

Replaces (OEM)

• 1395-9258
• 1399-1138
• 1399-1473
• F010790

Frequently Asked Questions

What carburetors does the Sierra 18-7057 needle and seat fit? It is designed for Tillotson AJ, CO, KA, KB, KC, KD, and WB Series carburetors, the type used on Chrysler/Force outboard motors.

Which Chrysler/Force outboard models use part 18-7057? This needle and seat assembly fits 120 HP models 1208/1209HD, HE, HF, and HG, and 135 HP models 1358HA, HB, and HC.

What is the bore size of the 18-7057 needle and seat? The bore size is 0.078 inch.

What OEM part numbers does the Sierra 18-7057 replace? It cross-references to Chrysler/Force number F010790 and Mercury Marine numbers 1395-9258, 1399-1138, and 1399-1473.

What material is the needle and seat made from? The Sierra 18-7057 assembly is made of metal for durability in continuous contact with fuel.

Is this an OEM or aftermarket part? The 18-7057 is an aftermarket Sierra replacement part manufactured to meet or exceed the specification of the original equipment needle and seat it replaces.

How much does the 18-7057 needle and seat weigh? It weighs 0.01 pounds.

What symptoms indicate the needle and seat needs replacement? A worn or pitted needle and seat in a Tillotson carburetor typically causes fuel flooding, hard starting, or a rough idle, since it can no longer shut off fuel flow properly at the correct bowl level.

What does the 18-7057 needle and seat do in the carburetor? It regulates fuel entering the carburetor bowl, with the float-actuated needle seating to stop fuel flow once the bowl reaches the proper level.

What color is the Sierra 18-7057 needle and seat? It is white.

Does the 18-7057 come as a complete assembly? Yes, the Sierra 18-7057 is sold as a complete needle and seat assembly, ready to install in a compatible Tillotson carburetor.

Should I confirm fitment before ordering the 18-7057? Yes, because needle and seat fitment is specific to the carburetor series and outboard model, confirm your Chrysler/Force outboard model against the 120 HP and 135 HP fitment listed for part 18-7057 before purchasing.