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Crevice flows of hydrocarbon fuel (both liquid and vapor) have been observed directly from fuel-injector mounting and nozzle-exit crevices in an optically-accessible single-cylinder direct-injection two-stroke engine burning commercial gasoline. Fuel trapped in crevices escapes combustion during the high-pressure portions of the engine cycle, exits the crevice as the cylinder pressure decreases, partially reacts when mixed with hot combustion gases in the cylinder, and contributes to unburned hydrocarbon emissions. High-speed laser Mie-scattering imaging reveals substantial liquid crevice flow in a cold engine at light load, decreasing as the engine warms up and as load is increased. Single-shot laser induced fluorescence imaging of fuel (both vapor and liquid) shows that substantial fuel vapor emanates from fuel injector crevices during every engine cycle and for all operating conditions.