Boat turns wrong way

[CapnCrunch]

my 83 Lancer 44' has two Perkins 4.236 engines with reversing starboard tranny turning 20x20 props. When she is sitting still in the water (i.e. waiting for a bridge opening) if I shift the port tranny into reverse at idle rpm, the bow starts turning to starboard instead of to port as it should. If I shift it into forward, it also turns to starboard, so the prop is not reversed as someone has suggested.

Any ideas?

 

[Benthic2]

The current and/or the wind may be the dominant force. Does it always happen the way you describe, or just in a certain location ?

 

[CapnCrunch]

It has occurred in several different situations. Unfortunately, I'm not always able to leave the helm in order to determine wind direction or which way the current is flowing.

 

[SteveK]

In comparison, doing the same with starboard, what happens.
It should be the opposite to port action.
If opposite to expectations, have the trannies been pulled and swapped along with the props comes to mind.

 

[CapnCrunch]

When I shift the starboard into reverse with the port in neutral, the boat turns to starboard as it should. This seems to be a recent development but the trannys have not been out or worked on recently. It's weird.

 

[O C Diver]

While I'm not sure, I would guess that what is happening is the boat is pulling to port which gives the perception of the bow turning to starboard. This is stern walk. With a single engine boat, the stern walks to port or starboard in reverse, depending on whether the propeller is left hand or right hand.

Ted

 

[mvweebles]

First, double check your prop shafts are spinning in the correct direction(s). Viewed from astern with gears in forward, the starboard should be turning clockwise, the port one anti-clockwise.

If it's a recent development, and you haven't whacked something, you might have some hard growth on your prop that is causing abnormal reactions. I cannot explain exactly the symptom you mention, but chances are pretty good something has taken-up home on your props or bottom.

Peter

 

[CapnCrunch]

O C Diver: Thats possible, I'll have to look more closely next time.

 

[CapnCrunch]

First, double check your prop shafts are spinning in the correct direction(s). Viewed from astern with gears in forward, the starboard should be turning clockwise, the port one anti-clockwise.

If it's a recent development, and you haven't whacked something, you might have some hard growth on your prop that is causing abnormal reactions. I cannot explain exactly the symptom you mention, but chances are pretty good something has taken-up home on your props or bottom.

Peter

I am able to open an engine room hatch and have verified that the prop is turning anti-clockwise. The boat is on the hard now and very little growth was visible on the prop, nor could I find any obvious defect.