Abstract: A carburetor for a scavenged two-stroke internal combustion engine has an enriched fuel-and-air mixing passage extending through a housing of the carburetor. Engaged to the housing is a body of an air flow modular assembly which carries a primary air flow passage which houses a butterfly-type control valve therein. The throttle valve of the fuel-and-air mixing passage is mechanically linked or cammed to the control valve of the air flow passage so that opening of the throttle valve soon after opens the control valve allowing additional air to enter and provide a leaner fuel-and-air ratio in the combustion chamber of the engine when running under load. The air flow modular assembly has a sealing-and-bearing assembly which eliminates air leakage from the surrounding environment along the shaft of the control valve and into the primary air flow passage. The sealing-and-bearing assembly has a bushing which inserts into a counter bore of a cylindrical bore which receives the rotating shaft of the control valve.

Abstract: A carburetor for a scavenged two-stroke internal combustion engine has an enriched fuel-and-air mixing passage extending through a housing of the carburetor. Engaged to the housing is a body of an air flow modular assembly which carries a primary air flow passage which houses a butterfly-type control valve therein. The throttle valve of the fuel-and-air mixing passage is mechanically linked or cammed to the control valve of the air flow passage so that opening of the throttle valve soon after opens the control valve allowing additional air to enter and provide a leaner fuel-and-air ratio in the combustion chamber of the engine when running under load. The air flow modular assembly has a sealing-and-bearing assembly which eliminates air leakage from the surrounding environment along the shaft of the control valve and into the primary air flow passage. The sealing-and-bearing assembly has a bushing which inserts into a counter bore of a cylindrical bore which receives the rotating shaft of the control valve.

Abstract: A carburetor for a two or four stroke engine having a diaphragm chamber for supplying fuel to the air intake passage of the engine, and a reservoir for primer fuel. A manually operable pump or bulb draws fuel from the diaphragm chamber into the reservoir. An outlet passage leads from the reservoir to deliver primer fuel to the engine. A normally closed manually operable valve or button is provided for opening the outlet passage. The capacity or the reservoir is varied as a function of ambient temperature by a temperature compensator.