What current prop is installed on the motor if any. If counting with one need prop brand/model, diam, pitch, material, max wot rpm achieved as usually loaded as a starter.
Right now isn't known if there's an installed prop as to check if motor is running under or over propped as loaded and go from there maximizing a prop if in need. If any the prop selector will help to select a prop as a starter one..
The correct one will need to be water tested as loaded and check if motor revs at least middle to max wot rpm range factory stated to state it performs well for your application.