Wandering heading at slow speed

sopicki

Cadet
Joined
May 24, 2022
Messages
13
Hi all,
Purchased my 1986 Cobia 189Xl Monte Carlo with OMC 3.0L 400 stringer September 23rd last year in Harrisburg PA and brought it home to Massillon OH. After much work with the help of those on this forum I got her in the water yesterday, I haven't been boating in over 5 years.....so nice to be back. I took her to the Portage Lakes State Park which is basically 7 lakes joined together with channels. There are two speed lakes but pretty much everything else is a no wake zone. The engine idled very nice and I ran her up to about 4000 rpm in one of the speed lakes. Aside from the speedometer not working I really have nothing mechanically (with the boat) to dig into. However at idle speeds the boat oscillates perhaps 5 degrees left and right when I hold the wheel steady. The drive unit is pretty darn solid so I don't know if this is a characteristic of this boat or a result of my removing the planes/wings? from the lower gear box. I've not done any research on the wings but assume they just help the boat get on plane faster but shouldn't affect the lateral stability of the boat. She was rock steady at just about any speed that would create a wake. Any ideas?
Oh and my trailer broke in half...
 

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racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
31,278
Think you need a new trailer.------If you repair that it will just fail somewhere else next month.
 

1960 Starflite

Petty Officer 1st Class
Joined
Jun 23, 2011
Messages
281
My Century does the wander thing too. Trim all the way down will help some. I think it's the nature of V-bottom boats. I changed out the prop to a 4 blade, cut half the chasing effect and improved hole shot.
 

sopicki

Cadet
Joined
May 24, 2022
Messages
13
Oh yes.....
I had a feeling that might generate some feedback.....Hahaha
I started looking for a trailer as soon as I got it home last year. I got a solid trailer a couple of months ago but it could use some paint to look as nice as the boat.
Since the trailer made the 5 hour drive from Harrisburg to Massillon no problem I was reasonably confident that it would make the 5 mile drive to the lake.....WRONG
I'll be looking for trailer restoration advice (for the new-to-me trailer) in another thread.
 

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sopicki

Cadet
Joined
May 24, 2022
Messages
13
I had a 1978 Crestliner 16' with a 1969 Johnson 55hp outboard for 20 years but never experienced the slow speed wandering with that boat. On that one you always had to hold on the the wheel with both hands at any kind of speed to keep the motor from trying to run off to one side or the other. It did sit a lot flatter in the water though, I noticed that the Cobia sits pretty low at the stern and I'm not sitting much forward of the center of gravity to get the bow down.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
69,320
Ayuh,.... You were seein' V-hull wander,.....
Most do it, in varyin' degrees,....
Just let it go, 'n don't fight it,....
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
10,024
Agreed my later model OMC with the Cobra system does the same thing pretty much.
As for the trailer, I wouldn't buy anything BUT a galvanized steel trailer here, mine is a '94 still in good shape, just upgraded the axle (to 6000 lbs) and brakes (12" surge) last year. It has a very long tongue so I don't have to put my Jeep's rear tires in the salt water.
 

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poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,903
Wandering at idle speed is normal for most V hulls, as others have noted.

The motor is pushing the boat, so at low speed the bow tends to wander as it tries to cut through the water. At higher speeds it has more force which allows it to cut straight through the water.

That's why it's preferable to mount a trolling motor at the bow rather than at the stern. This way the trolling motor is pulling the boat as verses pushing it. By pulling the boat it will steer straight.
 

harringtondav

Commander
Joined
May 26, 2018
Messages
2,241
Same response as several others above. Vee hull wander is common. My previous and current boat do it, as well as others I've driven. I'll adjust the steering a bit to get an average heading where I want to go. ....you'll wear your arms out trying to correct. I've read here that duo prop drives track straight.
 

flashback

Commander
Joined
Jun 28, 2002
Messages
2,263
The boat is 30+ so what you have is V+ wander. There's several places that get slack in the steering which can add to the natural wander..
 
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