Abstarct: The purpose of this study is to reduce the brake Specific fuel consumption and improve the performance of the Super Tiger 3000 engine. To achieve this goal, at first, the concept of the engine is define and then the thermodynamic analysis of the two-stroke engine is examine and technical characteristics of the engine is mentione. In the following, the functional characteristics, such as indicator and brake power, indicator and brake torque, indicator and brake specific fuel consumption was analyzed, and brake power, brake torque, and brake specific fuel consumption will calculate.In order to investigate the factors affecting the combustion process, the functional analysis of the engine is carried out using Lotus software. Various models of the software are used for engine analysis, which include the combustion function, the heat transfer model in the cylinder, the scanning model, and The friction model is considered.In order to investigate the factors affecting in the combustion process, the functional analysis of the engine is carried out using Lotus software. Various models of the software are used for engine analysis, which include the combustion function, the heat transfer model in the cylinder, the scavenge model, and The friction model is considered.According to the characteristics of the ST 3000 engine from the wiebe function with coefficients a = 5 and m = 2 for combustion, the Annand model for heat transfer, the Brandham Benson Displacement Mixing Model and Heywood model for friction was used. In the next step, to determine the optimum ignition angles of the engine, ignition timing system of the two-stroke engine, along with the design techniques the optimum advance was studied. The values of the engine performance parameters for the angle ignition are proportional to A10% (10% the mass fraction of the mixture fuel and the air is burnt) from the angle A10% =-26^o BTDC to the angle of A10% = 6^o ATDC , two degree two degree was compare and In each revolution, advance angle in which the engine performance parameters, including power, torque and ... were optimized, was chosen as the advance angle of the motor. For example, the output results of the software show that in the WOT, and at altitude 8000 feet, the value of optimum advance 15.2^o BTDC at 1000 rpm increased to 22.2^o BTDC at 4000 RPM and then reduced to 14.1^o BTDC at 10,000 RPM , which results in optimum advance angle, consistent with existing theories for Two-stroke engine. In the same way, the values of brake optimal parameters such as power, torque, etc. for the throttle θ= 15^o, 25^o, 30^o, 45^o, 60^o, 75^o and flight altitudes 0 to 20,000 feet was obtaine. With regard to the optimal performance of the engine, the engine fuel scheduling system has also been calculated at different airfrxame tracks and heights, and the duration and amount of fuel spray in the fuel injection process has been determined. With regard to the optimum performance of the engine, the engine fuel spray scheduling system at different throttle and heights has also been calculated, and the duration and amount of fuel spray in the fuel injection process has been determined. But the main part of the present research, is the design and construction Throttle Body Injection. According to the analysis, various parts of it, including the diameter of Throttle Body Injection, the type and thickness of the butterfly valve and its axis, along with the location and angle of the injector, were designed and constructed. In the following, airflow and fuel injection in the TBI system was simulated. The performance of this system in different operating conditions (in the 15, 30, 45, 60 and 75 degrees of throttle valve, engine speeds of 1000, 3000, 6000, 9000 RPM; flight altitudes of 0, 4000, 8000, 12000, 16000 and 20000 feet) was investigated. Observations indicate good accuracy of the models adopted for fuel injection modeling. Due to the thermodynamic analysis and the reliability of the operation of the throttle body the engine warm tests was performed and the comparison of the analytical, software and laboratory results is as follows: in comparison power diagrams of WOT, analytical diagrams have more values than laboratory results and Lotus simulations. The reason is non-consideration friction work in thermodynamic analysis. Also, comparing the injector and Carburetor power diagrams shows that due to better spray and atomisation fuel in the injector, the output power in the injector is higher than that of the cabercator. In the fuel consumption charts include analytical, Lotus simulations, injectors and carburetors, respectively, with the lowest fuel consumption. In the special fuel consumption, the lowest special fuel consumption is related to the analytical state and the highest special fuel consumption is related to the carburettor.