GI Auz wrote:
for the sake of future readers... got the answer from the local Merc specialist.
The power trim switch on the throttle lever has full down authority, however the up circuit is de-activated above about 5 deg up by the trim limit switch.
The trailer buttons have full authority through the complete up/down range.
Operation of thrust (power on) whilst the leg is above the trim limit range applies force through some of the gymbal structures that are not suppose to carry load, and can potentially lead to damage.
These sorts of statements from specialists bemuse me; the tilt angle is supposedly limited to prevent damage to the universal joints. Yet the steering angle range is far, far greater and the universal joints can't tell the difference really between up/ down and port/ starboard.
I imagine it's the combination of extremes of up/ down and port/ starboard which is the killer.