First thing to check and maybe you did.
There is a "stop" pin that can be moved further down, I am assuming
it is already down to the last position though, but just in case....
The cavitation plate should be able to be parallel with the line of the hull. If it goes less that is even better.
good luck.
~..~..~.. ><((((º>
Things done at the last possible minute are done with the greatest possible information. Procrastination is, therefore, the most efficient means of doing things.