The 233-669 Tillotson Fuel Inlet Needle, Seat, and Gasket Kit is often used as part of converting gas carburetors into methanol carburetors and the fuel inlet seat is sometimes referred to as an alky seat. 

This is because this seat has the largest orifice for flowing fuel in the Tillotson catalog. This doesn’t mean, however, that it is used only in alky carburetors. Its often used in gas carburetors especially rotary and reed valve 2-cycle race engines, big displacement piston port 2-cycle, and large 4-cycle engines. 

The Fuel Inlet Needle is known as an uncaptured needle. This is because the fulcrum arm lever does not “capture” the needle rather the lever tap sits on top of the needle. This is commonly used on a 4-cycle kart engine where the carburetor fuel inlet is usually facing upward. 

When replacing your seat it's important to measure the length and the fuel orifice to have the correct seat for your carburetor, especially ones that have been blueprinted, built, or modified.

Seat Orifice: 0.093”

Seat Length: 0.535"

Kit includes:

• .093” Seat

• Uncaptured Needle

• 16B-199 Copper Seat Gasket