Boat pulls to the left - help appreciated

[szarik5]

I have a 92 ts6m comp that I could steer almost with one finger. During one of my test runs with a newly and improved stronger engine, my nephew swears that a giant rock jumped out of the water and ruined all the brass and stainless thingies under the water line .

I installed new skegs, rudder, shaft and stem and now the boat pulls strongly to the left. The problem is most pronounced during acceleration. Grinding the rudder helped a bit but it did not fix the uncomfortable pull to the left.

If anyone has any knowledge on the below questions, please HELP!

1. Should the fins under the boat be adjusted and if so how to do it - including measuring proceedures.
2. Is the larger propeller and added HP doing it
3. Do I have the rudder ground the right way (right side of trainling and leading edge)
4. Any chance supra sent me the wrong stem

Cant think of anything else that could be affecting the pulling problem but any ideas would be greatly appreciated.

Ski

[01launch]

I hit something hard and my pulls to the right bad when on plane I think it is my prop because two fins on the prop are bent.

[szarik5]

Sounds to me like a bent strut - bent propeller will mostly cause only a change in performance and or vibrations. Change in angular thrust (p-factor) will have changes on the rudder but normally is very minor.

Look down the centerline of your boat and you should be able to look from the rear to line-up the fins with your head. The centerline shoul be down the center of your prop. My guess is that your strut is bent to the right.

Take a look and let me know - really interested if that is the case.
Ski

[riveredge]

szarik- we have a boat here that pulls to one side as well, and the ONLY piece of hardware changed was the rudder. The boat is a 1987 Pirata (23' DD), and we have been told the best solution is a no-feedback steering system, rather than grinding the rudder.

How much did you grind on the rudder? And did you grind the same side on the trailing edge as on the leading edge? Where did you get the information / advice on that?

[Ulsterboat]

I have a 92 ts6m comp that I could steer almost with one finger. During one of my test runs with a newly and improved stronger engine, my nephew swears that a giant rock jumped out of the water and ruined all the brass and stainless thingies under the water line .
I installed new skegs, rudder, shaft and stem and now the boat pulls strongly to the left. The problem is most pronounced during acceleration. Grinding the rudder helped a bit but it did not fix the uncomfortable pull to the left.
If anyone has any knowledge on the below questions, please HELP!
Cant think of anything else that could be affecting the pulling problem but any ideas would be greatly appreciated.
Ski

Is this a single screw left hand prop, with the rudder directly behind the prop?
If so this pull is likely caused by the propeller screw effect. To correct the pull to the left, attach [weld or bolt] a small light gauge s/s tab about 3" x 3" to the aft end of the rudder blade and bend it about 30 degrees to the left (not the right). Try this and adjust angle until boat steers a straight course.
Ulsterboat

[rludtke]

My Comp has always pulled slightly to the left, I always assumed that this was normal (due to P-factor and tourque), as I alway experienced this with airplanes. On airplanes we would trim this away at cruise speed with fixed tabs on the rudder, simular to what Ulsterboat described. I wonder if you simply exasperated a normal condition by the increase in tourque and P-factor resulting in your bigger prop and more HP?

If these boat are not supposed to be turning left under power, then I guess I would like to hear that from others, and pursue methods for making it stop too.