I have '74 650 on my 15 Ft Deep V Tri and since I have owned this boat I can't figure out why it pulls to the left so bad when at full throttle. I have tried adjusting the trim tab but not sure if I went the correct way with it. Can't seem to find anything in my service manual that explains it well enough either. Starting to wonder if it has something to do with the prop on it. Any suggestions would be appreciated. Thanks