Boat pulls to the right why?

[stubbsboogie]

I have just purchased a boat to upgrade from my smaller boat and am a bit out of my knowledge range on some things and need some help.
I have a 1998 18ft Glastron with a 2001 Yamaha 100hp four stroke
When I am underway the boat pull sto the right pretty badly, it is also hard to turn back to the left.
I thought it might be something to do with power steering but when it is shut down it turns smoothly. So I do not think that is the case.
Need some help because right now if you are not fairly strong the boat is difficult to drive.
Thanks so much for any input.

 

[Dhadley]

Re: Boat pulls to the right why?

I doubt if your boat has power steering. That's usually on larger boats with larger motor(s). You may have hydraulic steering bit it probably does not have power assist. In any case, steering torque is a normal function of a single prop turning in one direction. There is a torque tab underneith the AV plate right above and behind the prop. Looks like a small fin.

If your steering pulls to the right, move the tab to the right. Trim position has a lot to do with it too. If you over trim you may get steering torque too.

 

[stubbsboogie]

Re: Boat pulls to the right why?

Thanks for the tip. I adjusted the trim tab but with little or no effect. I removed the hydrofoil and that seemed to help alot but only on plane. Still pulls to the right at low speed and is still difficult to turn back to the left at low speed.
Is this just torque or is it something else I am not doing.
Thanks

 

[rodbolt]

Re: Boat pulls to the right why?

steering torque is created by the rotating mass underwater, most single engine rigs have a right hand prop, as this prop rotaes it not only develops fwd thrust it tends to try to move to the right, the result is feed back at the helm.
the trim tab can help.trim angle can affect it as can prop blade design.
however some hulls you have 3 options,hydraulic steering, a no feed back cable steering helm or live with it.
its not unique to any brand of engine its a simple law of physics.

 

[stubbsboogie]

Re: Boat pulls to the right why?

Thanks Rod
I can Iive with the torque steer but is there any way to make it easier to combat the difficulty in low speed steering to the left. As it is now my girlfriend cannot effectivly steer the boat to the left at low speeds.
Thanks again for all the help guys.

 

[MikDee]

Re: Boat pulls to the right why?

Thanks Rod
I can Iive with the torque steer but is there any way to make it easier to combat the difficulty in low speed steering to the left. As it is now my girlfriend cannot effectivly steer the boat to the left at low speeds.
Thanks again for all the help guys.

It sounds like you have something else going on here? Under the powerhead on the rotating assembly of the motor there should be a zerk fitting, or 2, get some marine grease, and pump it in there till you see it start coming out the joints, top, & bottom, it may be dry. If that don't help, maybe you need a new steering cable.

 

[stubbsboogie]

Re: Boat pulls to the right why?

I think it is lubed ok. If it was nt it would probably be hard to turn when not under power. I wil check the zerk fittings when i get back home to the boat. assuming they are fine. Is there an inexpensive way to work on the hard turning to the left.

 

[stubbsboogie]

Re: Boat pulls to the right why?

If I wanted to instal a NFB system do I have to replace the entire steering cable assembly or just the parts behind the steering wheel?
Thanks

 

[James R]

Re: Boat pulls to the right why?

Do you have the motor tilted at a steep angle. If so try bringing the motor up.

 

[DanMcK]

Re: Boat pulls to the right why?

I had an NFB steering system on my old 125 hp Force. It has some good and some bad issues. It works by locking the steering wheel in place, you have to use a bit of physical strength to overcome the mechanism and then you can steer.
My wife occasionally helped steering the boat at low speed couldn?t use the NFB system at all. I developed muscles I didn?t even know I had.

The geniuses who installed my new OB replaced the fairly new NFB system, with a whole new steering system. When I complained they stated,? Dan we couldn?t turn the darn wheel so we figured it was shot.?
The point is, it might be too much for your girlfriend.

All the advice so far has been good, let me add this.
1 Try adjusting the trim tab a little bit at a time.
2 Is the trim tab in good shape or has some one replaced it, maybe with the wrong one.
3 Is the trim tab a zinc anode possibly damaged by corrosion?
4 is the motor turning enough RPM to be in the correct operating range.
5 check out some other Yamaha 100 hp, owners may have a recommendation as to the pitch of the prop.
6 don?t over look grease or worn out bushings,

Most OB will pull but once on plane it shouldn?t be too bad.

 

[stubbsboogie]

Re: Boat pulls to the right why?

Thanks Dan,
Trim tab looks good, not corroded or damaged, I would guess it is the original one for the motor.
Once on plane it is much better after I adjusted it. There is some low speed veering but tilt angle can help and it is not too bad.
I have greased everything I can grease.
I am still searching for the problem. Only hard to the left, and at low speed. once boat is planed out it is perfect.
I think I am going to have the cables checked to see if that can have anything to do with it.
I really appreciate everyones help so far in this.