Motor offset and steering torque

[AndyL]

G'day all.<br />My current engine (150 Mariner)is mounted 1.5~2 Inches off the centre line to starboard. The boat is a heavy, deep V 21 foot offshore fishing boat, max speed about 35 knots. It has always had a hard pull to starboard even though the trim tab is full over (To starboard) at low to below planing speeds. Can anyone tell me if I was to re fit the motor onto the center line if this would reduce the steering torque at all. I am not keen to experiment as it means more holes in the transom unless anyone with experience of this phenomena can tell me what effect it would have.<br />Many thanks<br /><br />Andy

 

[sort]

Re: Motor offset and steering torque

Hydraulic steering or standard?

 

[Winger Ed.]

Re: Motor offset and steering torque

With the engine in the center, and the trim tab adjusted to a neutral position, it should be equally easy, or hard to steer in either direction.<br /><br /><br />Offset as it is, I'd think the engine would have more leverage to steer the hull to Port. <br /><br />Steering to Stbd, it would try to push the hull in a diagonagnal line straight ahead. Whatever bit of turn you got in that direction was due to the resistance- or rudderance, if there is such a word- from shape of the hull bearing down in the water, and forcing it over to the right.

 

[AndyL]

Re: Motor offset and steering torque

Hi all<br />Thanks for posting a response. I have standard (Teleflex/morse) steering. I see where Winger Ed is coming from but the reality is the opposite. It has strong steering torque to starboard, ie if I let go of the wheel at below 15 knots it will spin itself hard to starboard. Centralising the trim tab makes matters worse. At higher speed ie 25+knots life is much easier to control and at 30knots hardly any torque pull at all. From your suggestions it would seem that its not worth centralizing the motor as I agree it should be more biased to port in its present set up. Any more thoughts welcome.<br /><br />Andy

 

[robbyusa]

Re: Motor offset and steering torque

Do you have much steering friction because if not you may have a hard time tuning every thing to neutral pull at all speeds and conditions?

 

[AndyL]

Re: Motor offset and steering torque

Hi Robbyusa<br />There is no steering friction adjustment on the motor that I am aware of. I have just changed the motor this season from a 135 up to 150 and the steering effects are the same for both. I think as you rightly point out it may just not be possible to neutral out torque for the range of revs.<br />Andy

 

[sort]

Re: Motor offset and steering torque

Have had this same problem with a 175 Johnson on a 18.5ft bassboat. The engine torque is greater then the steering system friction and at low speed or poor trim the steering wheel would yank my hand off. My local dealer made an adjustment to the steering rod on the engine. He called what he did "binding" the system but I have been told that "you never bind a steering system" so what he did was "adjust" the system. By adjust I mean that you have to tighten down the steering rod guides to increase friction and thus this should counteract some of the engine torque. Just make sure that the steering is not "adjusted" to much as you don't want to have to fight the wheel too much. Another advantage to having a tight steering sysytem is that at high speed you are not as likely to make quick movements.<br />Good luck.

 

[AndyL]

Re: Motor offset and steering torque

G'day Fireman.<br />I reckon you are right however I am not keen on modifying by foul means the steering system when there is that much power hanging onto it. I think it is just a fact of life unless I change over to hydraulic steering at some affordable time.<br />Thanks for the interest shown. I have the whole of the winter to ponder whether to upgrade the system or not.<br /><br />Many thanks<br />Andy

 

[robbyusa]

Re: Motor offset and steering torque

This sounds a little crude but I once used a piece of 3 inch heater hose and two hose clamps to addd some friction to the steering on a OMC.<br /> just clamp one end to the pivot tube threads and the other to the cable. Then adjust clamp to proper friction. Worked pretty good also seals out water.<br /> I would suggest doing something as I was almost thrown by a boat when the steering spun.

 

[sort]

Re: Motor offset and steering torque

If you have a local boat tech who will talk with you without charging then I suggest you do that as this probelm can be dangerous if not corrected and as robbyusa said, you could be thrown from the boat.