Consider the possibility of buying a boat motor in a cheaper version and less power to themselves to alter it more powerful. Forcing basic motor with average characteristics will allow you to save money and to compensate for the difference in power.
Inspect your motor to determine the presence or absence of the restraining choke, check the specifications of the unit. This files most often have to be replaced flap valves, carburetor (nozzle), the exhaust manifold and the commutator.
To precisely determine what parts need replacement, then compare at the parts catalog set parts of your motor and the unit whose characteristics you wish to receive. So you will be able to identify the nodes that need improvement.
Remove the power limiter (small engines) and adjust the valve clearances. Another way to increase power motor - debugging components and parts responsible for suction and discharge. Operation to increase the power of the motor is produced individually for each type.
Make the bore of the carburetor of the engine by increasing the diameter of the diffuser. To do this, first disconnect from the carb spray (have to drill them over the brass tube), tube nozzle, throttle and choke cover float chamber and Unscrew the adjustment screws. The tube nozzles will be easier to dismantle by inserting in it a wire of suitable diameter. After boring reinstall the sprayer hose nozzle and other parts. Close the hole on the atomizer tube made of suitable size screw with a lock nut.
Ask for assistance to the mechanics of the service center if you have trouble when making design changes to the engine. So you will save time and nerves. Self-changing power of the motor can be a costly process.