Steering question

[mdemott]

2012, 20ft Bay Boat with 150 hp Motor, SeaStar steering

Steering is "lumpy" above 1100 RPM the steering wheel will turn normally about a quarter turn and then provide resistance. When you physically overcome this minor resistance it turns about a another quarter turn and then repeats. When engine is at idle turning is very smooth. Running a 14.2 x 18 RH three blade prop.
Drained and refilled the steering system in February 2017.

Anybody have any thoughts on this?

 

 

[Bamaskeet]

I would adjust the anode under the cavatation plate to see if it improves the situation.

[FROZEN]

32 minutes ago, Bamaskeet said:

I would adjust the anode under the cavatation plate to see if it improves the situation.

I think he’s referring to the adjustable torque tab above the prop. I’m not an expert, but he’s on to something.....it looks like a rigging/motor position issue more than a fluid/steer system problem. Do you have a jackplate? My 22TE is nearly impossible to steer when the motor is down and speed is high. Your problem seems to worsen with higher speeds/RPMs. As I raise the JP, steering improves to normal. Pretty much the same for all flats boats and I assume one of the major reasons they were invented. IOW...JPs do a lot more than allow shallow water running.

[HoneyB]

if the bump is somewhat repeatable as you turn the wheel I would think the valves in the helm are sticking and requiring more force to turn. I would search around for people having issues with sticky valves in sea star helms.

 You can take the  torque tab completely  off for a test run. if the problem persist no adjustment will improve your situation.

[jason p]

I don't think its the trim tab (torque tab, anode, whatever you wanna call it) on the cavitation plate. if it was, the steering would get progressively harder as your speed increased due to the increased pressure on the tab, I don't think it would be intermittent as you described either.

I would bet its the helm as stated above, the slightest bit of moisture manifests into a pretty sticky mess inside the helm over a period of time. I've had the same thing happen to me. The "valves" referred to above are little shuttle valves on the right and left side of the pump body that are held in place with a tiny spring and check ball behind the shuttle valve. The resistance you are feeling is hydraulic pressure (supplied by you through the wheel) overcoming the junk in the valve causing it to stick, once you let off the slightest bit of pressure, or the pressure in the pump body decreases due to the valve/valves sticking  the spring re-seats the valve and you have to overcome the junk again, and so on.

I would make sure the system is properly bled first, but you probably gotta rebuild it. Once you get over paying $40 for a couple O-rings and a gasket its pretty painless and straight forward. A dude on the The Hull Truth did a pretty decent article with pictures on the rebuild.

[mdemott]

Thanks to all who replied. Pinned it down to valves in the pump. New pump going in tomorrow just in time for the cold snap.

Thanks again.