Boat Goes Left Right Left Right Left Right, ect

jfmck_65

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Just bought a Sylvan 17 ft dect boat (1978) w Mercruiser 470 I/O took it out for first time and constantly have to correct steering side to side wont go straight. I know my way aroyund cars and mechanical stuff but boats are new to me Iv no clue where to start appreciat any help, thanks, jim.
 

Don S

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Re: Boat Goes Left Right Left Right Left Right, ect

That's normal for any IO or single engine Outboard boat with a single prop. Don't overcorrect.
 

achris

More fish than mountain goat
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Re: Boat Goes Left Right Left Right Left Right, ect

Go to the back of the boat. Grab the rear end of the drive unit and try (not too hard) to move it left anf right. If there is significant slop without the steering wheel moving, then you may need a new Gimbal ring assembly.

If not, or very little, slop, then what Don said.

Chris............
 

jfmck_65

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Re: Boat Goes Left Right Left Right Left Right, ect

I can move the outboard unit back and forth about 1/4 inch side to side and all of that movement is coming from excess play where the steering cable goes thru that piston or sleeve mounted horizontally just behind the transom.
 

Don S

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Re: Boat Goes Left Right Left Right Left Right, ect

That much play is better than most. Practice will make your zigging and zagging a lot less.
 

jfmck_65

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Re: Boat Goes Left Right Left Right Left Right, ect

Thanks much for the info will be goin out next week will try to get the hang of it, jim.
 

QC

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Re: Boat Goes Left Right Left Right Left Right, ect

A slight clarification . . . that kind of steering performance is normal at displacement speeds, i.e. less than 1000 RPM . . . If that is happening at planing speeds then you do have a problem. Otherwise as stated, very normal, lots of small steering input and anticipating the next one is best. V-hulls with I/O always behave like a drunken sailor at displacement speeds. Only known solution is trim tabs in the down position and that only makes it better, doesn't eliminate it.
 

luv2b0at

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Re: Boat Goes Left Right Left Right Left Right, ect

Maybe the previous owner is a veteran...:D
 

jfmck_65

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Re: Boat Goes Left Right Left Right Left Right, ect

not sure if prev owner vet but I sure am and yes left right left right burned burned in my brain. seriously though speed was very low was just enjoyin the senery. water was low and channel tricky to go any speed. OK if this is the way it is with these boats hard to enjoy a slow cruise in the sun. whole time was tryin to stay straight in the channel which is narrow anyway and when water is low you cant make any mistakes. hit bottom hard several times because boat didnt go where i steered it. if this is the way it it then this is first and last boat and will soon be for sale.
 

ziggy

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Re: Boat Goes Left Right Left Right Left Right, ect

OK if this is the way it is with these boats hard to enjoy a slow cruise in the sun. whole time was tryin to stay straight in the channel which is narrow anyway and when water is low you cant make any mistakes. hit bottom hard several times because boat didnt go where i steered it.
practice makes perfect jfmck. vhulls do wander at low speed. mine too. take yourself a boater safety class, this situation may come up in a class even. the basic statement is to look way ahead of where ya want to go, then with minor steering adjusments, you keep yourself on that heading. keep in mind that wind, waves and current factor into the equation too. also boats steer from the rear, unlike cars. the back moves over, not the ft. all this will come with practice. ya might see if you can find a body of water that is more forgiving than a narrow channel with a hard bottom too for the practice... all boats drive slighty different too i think.. good luck and don't let a little wandering around bum ya out. it can be overcome..
 

Don S

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Re: Boat Goes Left Right Left Right Left Right, ect

Very shallow, narrow channels are not exactly the best thing to idle through in an IO boat if you want to sight see without paying attention to the boat.
 

jfmck_65

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Re: Boat Goes Left Right Left Right Left Right, ect

ok, Will be goin out again this comin week will try different starting point where open and deeper water is closer to get to(west coast of cent fla, Homosassa). dont want to be a boat expert or mechanic just want to go out in the water ocassonially to cruise and fish. thanks for all the input really appreciate it, jim.
 

coastalcruiser

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Re: Boat Goes Left Right Left Right Left Right, ect

if your boat has trim tabs, try lowering them.
 

Alumarine

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Re: Boat Goes Left Right Left Right Left Right, ect

You might also try and go a tad faster to see if the handling improves at the increased speed.

They will go nice and straight at some point, although that might be too fast for your situation.

But, as Don mentioned, narrow and shallow isn't that much fun in most boats, especialy if you throw in some traffic.
 

a70eliminator

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Sep 9, 2007
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Re: Boat Goes Left Right Left Right Left Right, ect

I installed a set of sx smart tabs on my 20' deep v i/o and the wandering was eliminated completely and it wandered terrible before the mod. now even my kid can steer it a straight line.
 

FB Coach

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Re: Boat Goes Left Right Left Right Left Right, ect

Another vote for lowering trim tabs. It took my wandering away.
 

achris

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Re: Boat Goes Left Right Left Right Left Right, ect

Same with my boat, like a drunk pig off plane, straight as an arrow above about 11 knots. Thinking of getting some trim tabs... thinking more now...:p:p
 

windsors03cobra

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Re: Boat Goes Left Right Left Right Left Right, ect

With a 30 year old engine powered boat you need to be a mechanic and heed good expert advice when you get it.
Try some bigger water or maybe a kayak in that channel..... :p
 

mthieme

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Oct 6, 2007
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Re: Boat Goes Left Right Left Right Left Right, ect

You're lucky you don't have a Berkeley drive. I have one that goes from side to side so dramatically, I have to tow it out of the 6 knot zone.
 

jfmck_65

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Re: Boat Goes Left Right Left Right Left Right, ect

OK what are sx smart tabs and where on the motor do they go?
 
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