Boat Pulls Right...dangerously.

[mattkenton]

So i have already adjusted my trim tab on the foot and it helped a little. But it still pulls until i trim up. I am missing a large section of my skeg and it is soon to be fixed. Will this repair help any? WHat other variables cause pull? Sort of stumped. Thanks.

 

[tschmidty]

Re: Boat Pulls Right...dangerously.

Shouldn't be the skeg affecting it that much. How far off of center is the trim tab pointed? Should be no more than about 15-20 degrees. How far do you have to trim up to get it to stop? Is the outdrive fairly vertical when the boat is loaded normally and at rest?

 

[Grand Larsony]

Re: Boat Pulls Right...dangerously.

Is this a new boat (to you) and has it ever worked properly? When did it change (and what happened at the same time)?

 

[seedlings]

Re: Boat Pulls Right...dangerously.

Make sure the motor is 'plumb' straight up and down and centered on the transom. Mine was higher on the left, pushing the boat further to the right.

CHAD

 

[mattkenton]

Re: Boat Pulls Right...dangerously.

Shouldn't be the skeg affecting it that much. How far off of center is the trim tab pointed? Should be no more than about 15-20 degrees. How far do you have to trim up to get it to stop? Is the outdrive fairly vertical when the boat is loaded normally and at rest?

The tab is almost all the way over as far as it will go. It takes a bit of trim, not a ton to get it the free up the pull. Maybe 5 seconds of trim UP.


Is this a new boat (to you) and has it ever worked properly? When did it change (and what happened at the same time)?

Yes, new boat to me. Was this way when i bought the boat. Attributed it to the skeg.


Make sure the motor is 'plumb' straight up and down and centered on the transom. Mine was higher on the left, pushing the boat further to the right.

I will check this and get back to you. I guess just measure from the bottom of the transom on both sides to see if it is equal distance on both sides?

 

[Rocky_Road]

Re: Boat Pulls Right...dangerously.

Also make sure that the trailing edge of the trim tab is pointed to the direction that you are pulling. In other words if your boat pulls right, then the TRAILING edge needs to go to the starboard.

Happy boating!

 

[mattkenton]

Re: Boat Pulls Right...dangerously.

Make sure the motor is 'plumb' straight up and down and centered on the transom. Mine was higher on the left, pushing the boat further to the right.

Ok, so the Starboard side of the engine is one inch higher than the port. Unbolt and adjust with jack i guess?

 

[Fed]

Re: Boat Pulls Right...dangerously.

Whenever the prop shaft is not running parallel to the water surface the prop will load one side more than the other.
It happens because of the attack angle of the blade on the up stroke compared to the attack angle of the blade on the down stroke.

 

[fishertim]

Re: Boat Pulls Right...dangerously.

I have the same problem with my boat. A 16 foot aluminum bass boat. I've raised the speed wheel mounted on the transom up flush with the bottom of the boat. It was 3/4 inch below. I haven't had it out yet to see if that solved the problem. This my first boat and I'm trouble shooting each problem one at a time. I installed an automatic bilge pump a week ago. I turned on the switch and loaded the bilge with water and the pump came on when the water got a couple of inches deep. I really need to get it in the water to test the pulling right trouble though.

 

[mattkenton]

Re: Boat Pulls Right...dangerously.

Well i remeasured and everything is plumb.

Whenever the prop shaft is not running parallel to the water surface the prop will load one side more than the other.
It happens because of the attack angle of the blade on the up stroke compared to the attack angle of the blade on the down stroke.

Do you think if i were to adjust the thrust rod that would help get the prop more parallel on start?

 

[Fed]

Re: Boat Pulls Right...dangerously.

If you're talking about the rod that slides through the transom bracket to limit the trim travel then yes, I've got mine set in the bottom hole because anything past that is a waste of time.
I suspect I could even raise it up to the next hole and still have more than enough down trim.
Ideally the trim is set to push your boat forward, bow up / bow down is best adjusted with forward aft weight adjusted to your preferred cruising speed.

The little trim tab is purely there for engine torque (not prop torque), your crankshaft is trying to spin clockwise so your engine block is trying to turn counter clockwise.