This thesis covers the design and prototyping of an electronic throttle control (ETC) system for a small two-stroke engine. The thesis work is being realized in collaboration between a cooperating company and KTH. The throttle control system is veried with a physical combustion engine. The development process of the control systems is being done mostly in-house in the cooperating company. The company has developed electronic control of fuel and ignition system. In addition to the ETC throttle control system this thesis work also develops a control system of the angular velocity of the combustion engine by controlling the intake air to the small two-stroke engine. Today the air supply to the engine is controlled by a valve mechanically connected to the trigger/gas pedal operated by the user. The focus of the thesis is to investigate the advantages and drawbacks of implementing an electronically controlled air supply to a small two-stroke combustion engine. This master thesis discuss the detailed system design requirement of an ETC system for a small two-stroke engine. The result of this master thesis shows that it is possible to have velocity control on a small two-stroke engine, also minor improvements in acceleration of the small combustion engine is shown when using the ETC system. / Detta examensarbete omfattar design och prototypbygge av ett elektroniskt gasreglagesystem (ETC) for en liten tvataktsmotor. Examensarbetet utfors som ett sammarbete mellan ett sammarbetande foretag och KTH. Gasreglagesystemet verieras med en fysisk forbranningsmotor. Utvecklingsprosessen av styrsystemet bedrivs mestadels internt hos det sammarbetande foretaget. Foretaget har utvecklat elektronisk styrning av bransle och tandsystem. Utover det elektroniska gasreglagesystemet har detta examensarbete ocksa behandlat utvecklingen av ett styrsystem av vinkelhastigheten hos forbranningsmotorn genom att styra insugsluften till den lilla tvataktsmotorn. Idag styrs lufttillforseln till forbranningsmotorn av ett spjall som ar mekaniskt ansluten till avtryckaren som manovreras av anvandaren. Fokus for examensarbetet ligger i att undersoka for- och nackdelar med att implementera ett elektroniskt styrt luftspjall till en liten tva-taktsmotor. Examensarbetet behandlar det detaljerade designkravet hos ett ETC system for en liten tvataktsmotor. Resultatet av detta examensarbete visar att det ar mojligt att ha hastighetsstyrning pa en liten tvataktsmotor, aven sma forbattringar i acceleration pavisas nar ETC systemet anvands.