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Torque steer 1992 Johnson 150

D

David Nix

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" At speed, I must keep both h

" At speed, I must keep both hands on the wheel or it will turn hard to one side. The other side is easy to turn to and it will turn on it's own to that side if you let go. It is on a Hurricane deck boat 19 foot. It has always been that way, it's not something new. I just did not think there was anything I could do about it. "
 
" David,

The problem you ar


" David,

The problem you are dealing with is caused by the rotation of the prop; the trim tab on your outboard is made to combat this problem. You can adjust the trim tab so that it put's torque on the outboard in the opposite direction to help keep it straight.

The best solution is to go with No-Feedback steering; most modern systems for outboards are this way. What No-Feedback steering does is prevent force from being transfered from the outboard to the wheel - so more or less the engine is locked in the position you leave it in, it also makes steering much easier. To upgrade you probably can just replace the helm and stick with the same cable for under $100; if the cable will not work with the new helm, the whole system is about $180 and well worth it.

Jon "
 
"David.... In addition to Jon&

"David.... In addition to Jon's reply, to compensate for the pulling action, move the trim tab in the direction of the pulling a little at a time. Eventuially you will cancel the pulling problem out. I mention this due to the fact that some boaters confuse the function of the trim tab, and move it in the wrong direction which compounds the problem.

Joe
"
 
Re: "David.... In addition to Jon&

To be clear, my trim setting is untouched since I bought the boat 2 months ago & I guess it is not at its full limit, rather its 2 notches away, nearly full to port.

Heres the pic:
trim tab.jpg

"...to compensate for the pulling action, move the trim tab in the direction of the pulling a little at a time...

Joereeves, what you say does seem counter intuitive, though I guess I hadn't really considered all of the forces at play... & now I think I understand why you're right.

I have some experience in aviation & what you say would counter traditional "trim" wisdom on an airplane. Lets say a jet or a twin engine airplane is out of trim and yawing to the left, you move the rudder trim surface the right to counteract that yaw. Single engines airplanes do suffer from torque steer too, though I hadn't considered my problem from that perspective before now.

So, I guess we need to move the trim tab in same the direction as the torque steer because that creates a larger surface area for the propwash to act against to correct the torque steer, thereby pushing the motor in the opposite direction. Interesting...

Again, I haven't touched my trim tab, because I had assumed correcting a turn to starboard required trim adjust to port & my tab is already -mostly- to port. Just like joereeves said.

Someone needs to do a 3d fluid flow simulation & post to youtube so people can better understand this phenomenon. There isn't much info out there on how this really works. Just lots of info saying "here's your trim tab, adjust it to correct torque steer", offering no further guidance.

Before I throw down on a hydraulic or NFB kit, I will start by adjusting my trim tab about half the distance to full starboard from its current position & will report back next time I splash the boat.

Thanks for the help in getting my head wrapped around this issue!
 
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