The FT009 is one of the most popular entry level RC boats. It is cheap but quite reliable. However, when it comes to prop upgrade, it is often found that the motor can cook itself pretty fast. Upon closer look it won’t be a surprise to find that heat dissipation is less than 50% – the coil covers only half of the motor!

The boat comes stock with a 540, which may be too short for a full blown coil (you don’t want the openings to be blocked).

The following photo shows a mod where a longer 550 is installed and is fitted with a full blown coil. The motor mounting plastic has to be trimmed to accommodate the coil.

With this configuration, a larger prop can be used without burning the motor and the ESC.  The prop shown below is 40. It is powered by a 550 motor and 2S power.

Another recommendation – replace the plastic shaft cup with a normal metal one. Refer to this article for further information:

Once you switched to a larger prop, you may start to see problem on weight balancing. Relocating the battery or adding small weight to one side of the boat may become necessary (especially on FT009).  Turn fins will also help in stabilizing the boat.