not sure on the motors kv but it is designed for a 3d profile plane and the recommended prop is around the 9 inch dia x 50 pitch. if i hold the model in front of me and hit full power it does have some pull and plenty of air pushing back. as you guys mentioned i will remove the air rudders and make up a water rudder then see how she runs, its a shame i have to remove the air rudders as this hull if you call it that goes over the water lillies with no issues plus its like a hovercraft on land. oh well for now back to the drawing board. i will let yous know results soon. thanks guys.