Can anyone help?

I have built a Dateline marine Cheroke Chief using my Irvine .20 with submerged drive to try and keep things cheap and simple LOL.

The thing is, it won't turn right!!!!!! Radio seems to be working fine but it leans into the turns and then seems to dig in and spins off in the opposite direction. Adding trim tabs to the outer edge of the tramsom hasn't helped.

The only thing I can think of is that the set up is wrong. The prop shaft angle is 10 degrees. The COG could be to far forward.

Any ideas?