How true/straight should a boat run?

[hooah212002]

Another "i just got my first boat and am generally clueless" question. the boat in question is an '87 Tracker Tournament V17 with a '92 Mercury 75HP.

 

Generally speaking, I have to fight against the boat to drive it straight, be it on plane or just cruising along. I have tried adjusting the engine trim and it helps some, but it still seems to pull one way or another and I'd not every be able to take my hands off the wheel for even a second. The prop spins counter clockwise and the trim tab is turned as far left as it will go. I am just curious if this is a normal condition or indicative of a larger problem with the boat.

 

Thanks!

[A-Jay]

Because a picture is worth a thousand words and to ensure we are all on the same page - 

Perhaps post a few pics of the stern (back) of your boat on the trailer.

Ensure that they include a clear view of your entire transom, your prop and the entire lower unit.

Could be quite helpful 

A-Jay

 

[hooah212002]

1 minute ago, A-Jay said:

Because a picture is worth a thousand words and to ensure we are all on the same page - 

Perhaps post a few pics of the stern (back) of your boat on the trailer.

Ensure that they include a clear view of your entire transom, your prop and the entire lower unit.

Could be quite helpful 

A-Jay

 

Good point. It's at my dad's house right now so I'll get some later today. Thanks.

[Way2slow]

you have a serious problem it what you posted is fact.  You are running a counter rotating motor and the boat is not setup for that. 

The prop should be spinning clockwise in forward gear and the trim tab should be turn so the rear edge of it is to the right.  If you look at it, you will see a built in curve to the right until you get a neutral steer with the boat up on plane and trimmed properly.  The natural torque of the prop wants to push the motor in a way that makes the boat want's to go to the right and the trim is just to fine tune that.  It will not correct an improper setup.   

 

One of the major causes of hard steer in one direction is the motor is not trimmed up properly, making the hull plow through the water, cause way too much drag.

Another thing that can cause it is a hook in the hull, usually caused by a trailer with center rollers and one of the rollers is up too high, which over time causes permanent damage to the hull.

If the motor is too deep in the water, that can cause hard steering torque.

 

[hooah212002]

13 hours ago, Way2slow said:

you have a serious problem it what you posted is fact.  You are running a counter rotating motor and the boat is not setup for that.

 

How do you know/how can you tell what prop rotation direction a boat is set up for?

[Way2slow]

Counter rotating motors are normally only used with a twin motor setup to counteract the torque of the normal motor and not give you twice the torque you would get if you tried to run two clockwise rotating motors. 

I have never seen anyone run a counter rotating motor as a single, stand alone motor.  I guess it could be done, but since I've never seen that type setup, I actually can't really say how it would react.

[WIGuide]

Being that the motor is only a 75, I'd be guessing it's not a counter rotating motor. Steering torque is normal and on a boat like yours that doesn't have a no feedback system, or hydraulic steering, being able to take your hands off the wheel on plane would actually be fairly rare. Way2slow, gave you some good info on the causes of excessive steering torque so I would check those out.