The job of a Subaru carburetor is mix a precise amount of gasoline with air so it burns into proper combustion and enables the engine to run properly. Improper fuel mixture from a carburetor will lead to the engine not running and possible additional problems depending on the amount of fuel. If too little fuel is mixed with the air, the engine "runs lean" and could potentially be damaged. If too much fuel is mixed, the engine "runs rich" and either wastes fuel, regularly stalls, or runs with very smoky exhaust.