Steering Stiffens with speed

[Yosef]

My cable-based steering is easy and smooth as silk from lock to lock with the engine at idle but when I spin up the motor it gets stiffer and stiffer with speed.

I don't think it's the trim tab as it's approximately as difficult to turn the wheel either way.

There's a bit of a "breaking free" effect when initially turning the wheel but even then it's hard to turn after it's broke free.

The boat has a King Marine AutoPilot AP2000 and the steering is so stiff that the AP can't turn the wheel when the engine is spinning above 2,000 RPM.

The outboard is a 2004 Suzuki 90HP with the third zerk on the steering/tilt tube so the steering cable end is very well lubed.

The engine has a permatrim installed and, per:
https://www.permatrims.com/category_s/12.htm
the engine is 1.5" lower than permatrim recommends. I'm not sure if this would cause the stiffness?

-Joe Dowd

[thataway]

There could be several reasons for the cable stiffness/steering issues. That it increases with speed (pressure on the motor/lower unit, and mount is increased) makes several more scenarios likely.

First bring the motor up on the transom, so that the permatrim is just on, our just barely under the top of the water at full planing speed--lets say 20 mph. If it is running fully under water, then the motor is too low. this should be with the permatrim parallel with the surface of the water.

Next is the condition of the cable--unfortunately, the cable steering does deteriorate with time in the tube. Increased work load (higher speeds) means more friction thru the entire system. That means to replace the cable and in some cases the head steering unit.

Finally the auto pilot mechanism could be an issue, with increased drag on the entire steering system. I have never owned a "King Autopilot"--and I believe that they are out of production, although a rebuilt unit can be purchased. I did look at the web site and the pilot motor fits over the shaft of the steering mechanism--be it push pull single cable, or open cables in an loop between the motor and the wheel that runs through several open pulleys at each right angle of the turn. I have to assume that you have the push/pull type of cable.

I would first raise up the motor on the transom, And check how freely the motor turns on its vertical axis and the transom mount. You can use a temporary tiller, and even measure forces with a standard fishermans spring scales, where there is a hook to catch one end of the tiller arm on the motor and pull on this to measure steering pressure in lbs to compare at various speeds.

Also at this time, be sure that the clutch of the King is fully releasing when in "Standby mode". Again use the tiller arm spring scale to see how much pressure you need to move the motor to freely allow the motor full range each way. Be sure that there is no clutch drag, or increased friction in the gears of the steering box, which fits around the steering wheel shaft. It might then need gear lubrication in the mechanism. Adjustment of the clutch, or a new unit. You also may want to watch the voltage drop when the pilot seems to be decreasing (There are ways to determine the amp draw, but for this diagnostic case, probably turning the motor itself is adequate,

Since this is a new "development" (Is it?) then it is. likely a number of small issues in each of these facets of the autopilot steering. Let us know what you find.

[Yosef]

[tsturm]

Try trimming the engine differently while under load.

[thataway]

Did you ascertain that the problem is the deterioration of the steering cable? Do you currently have the "non feedback" helm unit? Did you raise the motor to proper height?

[Yosef]

[ssobol]

Maybe now's the time to replace the steering with a hydraulic system?

[Yosef]