Boat pulling to right getting onto plane

Guys, found an old thread on this and could not find an answer. So, here's what I got: My trim fin(or whatever it is called) on the motor(40HP 4 stroke) was straight when I got the boat. When I powered up to get on plane, the boat has always pulled HARD to the right. As I got on plane, I kept trimming the motor up and the steering went neutral,(this is what my dealer said to do). I was told this was not correct. So, I changed the angle on the fin recently so that (from the back of the boat) the back end of the fin was pointing right to hopefully help the initial problem with the steering until I could get up on plane and start trimming. It got worse after this adjustment, and even with trimming up now, it pulls slightly to the right. So, what would you do? Put the dang thing back to 'straight' and live with the hard pull to the right until I can get it trimmed up, or try something else. I guess I could try to move the 'fin' so that the back of the fin points to the left and see what happens. All I know is that if I let go of the steering wheel now when getting on plane, the boat will do an immediate 360 turn until I can find the proper trim level. I can deal with this, but I have to make sure if ANYONE else is driving the boat, they must hang onto the steering wheel until they can get the motor trimmed.

Go some more to the right. Does not take much!! Never to the left unless you have counter rotating prop.

If it's pulling right, adjust the fin in the direction of the pull, which would be to the right.

If you can't get it corrected with the fin adjustment, it could be something else going on like your motor mount height....but being only a 40 hp I would doubt that would be having too much of an impact.

do you have one of the add on whale tail device that is supposed to help get on plane? I have seen those cause boat to drive bad

Guys, thanks for the replies. The 'fin' I was talking about is just below what I think is the 'cavitation' plates on the motor. You loosen the nut and you can turn the 'fin'. If all else fails, I'll set it back to 'Center' and deal with the 'pull' getting up to plane until I can get the motor trimmed up and the steering goes 'neutral'. This is usually only 3-5 seconds. Just CANNOT let go of the steering wheel during this time.

the hydro foil or whatever its called, mounts to cavitation plate. you might not have one

Turn your trim tab to 1oclock, and go from there.

Bassing, Art, again thanks for the help. Bassing, I don't have anything but a small 'fin'. Art, I think you are correct. I will make some adjustments in the driveway before my next trip and see. This time, I will bring the wrench and socket I need to adjust as you say before I get there and if the ramp isn't busy, and do some more testing/adjusting while I'm there Not a big deal, just hate that on the initial start the dang thing pulls hard to the right until I can find the correct trim adjustment. The boat gets on plane quickly with the 40HP/16ft boat. I 1st thought that when I was the only one in the boat that the right pull was due to my 190lb butt on the right side of the boat. But, even with another 190lb person on the left side, it does the same thing.