Hi all, had a strange occurance this past weekend. I have a 92 sailfish with twin 200 HPDI's; while out cruising this past weekend boat wanted to take a left turn. Best I can compare it to is a car being out of alignment. Any ideas? More info? Had a similar incident last year towards seasons end and thought I had it figured out when I pulled boat for the season and noticed the zinc on the port lower unit was loose.
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strange turning issue
- Thread starter fastal
- Start date
Rumford Grady
GreatGrady Captain
I had an issue where my Seafarer was listing to stbd while U/W. I determined that it was the zinc on the anti-cavitation plate. When I replaced my waterpump over the winter I had placed the "skeg" of the zinc in-line with the centerline of the engine.........the natural torque force of the prop caused the boat to heel. I slightly rotated the zinc tab and I'm at even keel.
Are these counter rotating motors or same rotation?fastal said:Hi all, had a strange occurance this past weekend. I have a 92 sailfish with twin 200 HPDI's; while out cruising this past weekend boat wanted to take a left turn. Best I can compare it to is a car being out of alignment. Any ideas? More info? Had a similar incident last year towards seasons end and thought I had it figured out when I pulled boat for the season and noticed the zinc on the port lower unit was loose.
counter, i did have a yamaha shop do water pumps this spring before I splashed.....are you thinking the lower units were reversed?
Curmudgeon
Well-Known Member
Enough Already
Well-Known Member
Had to read your last comment twice before getting your point. I assume if the lower units were swapped accidentally, there would a more dramatic problem than a slight alignment issue. Prior replies are more likely right on - check your cav plate zincs to ensure they are aligned straight back (for twins). They can come loose over time.
figured there would be much larger issues as well if there was an accidental lower unit swap. i did check the lower unit zincs when I came in and they were both tight and straight back
bayrat
GreatGrady Captain
You can also replace those torque tabs with a flat version that has no tab, yet still is a sacrificial zinc. Most twin setups come that way now as there is no need for the torque tabs if you have counter rotating engines; but if you put the ones you currently have straight back ,as mentioned before, that will be ok too.
fastal said:counter, i did have a yamaha shop do water pumps this spring before I splashed.....are you thinking the lower units were reversed?
I didn't suggest that the LUs were reversed (although that is an interesting thought) but rather my point was that mis-adjusting the tabs make a bigger difference on similar rotating LUs than on CRs.
Of course, if the tabs have curvature, there is a CR and normal version. Using a regular curved tab(cupped) on a CR unit will make prop steer worse.
You can also use anodes with no tabs when a CR and normal lu are used.
I suspect in your case that either a regular rotation curved tab was installed, or the tabs were not set correctly
If the lower units were swapped you may get less lift but other that that not much else. It's the same motor for std and counter outboards, only the counter lower units are set up "backwards" inside. Was there a lot of wind or current?
there was both wind and current, but i was going with the current and wind was coming at me from the port side. that was one of my initial thoughts as well but since I had a similar occurance last year I thought it was something more.