The level of hydrocarbon (HC) emissions, from a spark-ignition engine using a 30 % iso-butanol-gasoline blend was experimentally investigated. Experiments were conducted on a Hydra single-cylinder, spark-ignition, fuel-injection engine. HC emissions were measured as a function of fuel air equivalence ratio, ignition timing and engine speed. The effect of varying the temperature of cooling water on HC emissions was also investigated under three fuel air equivalence ratios (lean, stoichiometric, and rich). Results show that retarding ignition timing with respect to maximum break torque (MBT) has a great effect on HC emissions reduction, where for lean mixture, Phi 0.85, retarding ignition timing by 6 degrees from MBT reduces the exhaust HC emissions by 12 %. The level of HC emissions is also reduced by 30 % at MBT, as the cooling water temperature increase from 55 to 90 C. It is noticed that as the engine speed increases, the level of HC emissions decrease.