[TG] [TG11] ST4000+ starts hunting at higher cruising speeds

[Greg McKenzie]

I am brand new to the Forum but have an old Autohelm that came with a cruising sailboat we purchased two years ago. (38 feet)
After calibrating the compass with <5* of variance I was excited to get the vessel moving forward in calm seas up to her cruising speed of 6.5 knots.
Between 3 and 4 knots of making way the pilot held fine with the drive making slight adjustments. When I reached 5.5 knots the boat starts veering starboard/comes back to port past centre/continues to port then comes all theway back again. At this point I need to take control back and put into Standby mode.
Reading the manual many times I have played with rudder gain (left it at 6) and also made sure there was no metal objects close to the compass.
Any thoughts?
I am crossing my fingers there is a command fix for this.
Cheers.
Greg McKenzie

[Tom - Raymarine - Moderator]

Hello Greg,

I assume this is a Wheel system rather than ST4000+ Tiller? If wheel, does it have a rudder-position sensor (do you see rudder-angle on the display when in Standby)?

The ST4000+ wasn't as clever as the modern pilots and reasonably often behaved like that if on a wheel-steered boat with no rudder-reference. Later 4000+ Wheels were bundled with the rudder-reference for this reason. I would guess that you will see a lot of benefit from a rudder-reference, part M81105.

The 4000+ often wouldn't recognise a newly-installed rudder-reference: if this happens, go into Dealer Calibration (https://raymarine.app.box.com/s/nwf2s5ha.../720705051) and change the Pilot Type from 4000 Wheel to something like 5000 Hydraulic, save-and-exit, power-cycle, change back to 4000 Wheel, save-and-exit, power cycle and you should be good to go.

Regards,
Tom

[Greg McKenzie]

Thanks for advice Tom - - will explore this option. Greg