Twin sterndrive steering toe in?

Discussion in 'Sterndrives' started by rosbullterrier, Apr 12, 2012.

  1. rosbullterrier
    Joined: Feb 2005
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    Location: Cornwall, UK

    rosbullterrier Junior Member

    Is there such a factor to consider in setting up the steering arms between outdrives for best steering?

    I have 800 OMC Stringer outdrives; no don't dismiss that!
    The straight ahead steering is very jittery - overcorrects a lot.

    Now as a car mech I appreciate toe in will cause this and toe out would create a more vague steering.

    Maybe I havn't read the manual properly yet. Might setting the props to point inwards or outwards slightly cause this?
  2. IMP-ish
    Joined: Jan 2011
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    Location: united states of america

    IMP-ish powerboater

  3. tunnels

    tunnels Previous Member

    Toe in or toe out thats the point !!
    Best place to start always is neither one nor the other but perfectly straight !!From there its a individual thing ! each boat behaves differant to the other so really theres no black and white just shades of grey .
    Counter rotation in some cases dosent really make any differance at all and even changing the counter roataion from one side to the other doesnt make any noticeable differance as well .
    Standing in the back of the boat looking aft if the aft ends of the drives are toe out they will have a tendancy to cause the nose of the boat to rise a little and if they are toe in the nose of the boat has a tendancy to drop a little . with a adjustable link between the two units you can do a little easy trim things by yourself . with outboards not only toe in or out but sometimes one outboard trimmed up a little can hold the hull from wanting to roll from side to side as well as track straight .
    One company i worked making tunnel boats the set up and taking the owner on a teaching and show what happens trip was just a part of the hand over .
    Fine adjustment can and does make a big differance to the steering , tracking and handling of any boat regardlss what it is !!, Again with out boards the motor height has a lot to do with the final feel of things out on the water .
    The adjustable link with twins is very important to keep controll at all times .
    Jittery and skittish can also be slack or play in joints or cables or things that have come loose
    Just a fraction of play anywhere is emphisized and amplified dramaticly with each lack sloppy joint or steering cable play so thats a good place to check before you cast off from shore !!.:idea::confused::(
    When all is well you should be able to point the boat and let the wheel go and the boat should track in a straight line and without touching anything if you move to the other side of the boat it should very gradually turn ever so slightly in that direction all by its self .
    A perfectly set up and balanced tunnel with twin outboards will go for miles in a straight line and never have to touch the wheel.
    And in the open sea will slide a couple of degrees one way going up a wave and side a couple of degrees the other way going down so all in all its a straight line and again never have to touch the wheel !!. i love tunnels !!
  4. rosbullterrier
    Joined: Feb 2005
    Posts: 83
    Likes: 2, Points: 8, Legacy Rep: 21
    Location: Cornwall, UK

    rosbullterrier Junior Member

    Very grateful for your replies gentlemen.
    I shall play with it to find the optimum; no point in going off at the wrong angle without asking advice!
    All steering is renewed including the teleflex system and steering lever connections. It's not too easy to measure whether the outdrives are pointing directly back, the transom having a curve (and the boat's now permanently in the water)
    Yes both props turn the same way. Ahwell- glad you didn't dismiss that as unusable! I have yet to adjust the trim tabs.
  5. tunnels

    tunnels Previous Member

    Do you know your boat ??

    Are the trim tabs adjustable with buttons or a lever for each?
    Knowing your boat is something not to many people have learned , What does it like to do ? what doesnt it like to do ? and if you do this that will happen . take it for a run get over the hump and just stay at that speed take note of where the water spray comes out the side of the hull If its foward its nose down if its aft its nose up some where inbetween is where it wants to be !!,so set the tachos at say 2500 and watch what happens as you slowly trim !! first down and the nose drops and the tacho will drop a fraction as well because its harder to push !!,slowly trim up the motors will tell you as they find where they want to be the rpms should pick up !,the motor sound will change and become quieter and the spray out the side will
    have shifted aft a little !!,keep going with the trim and you will pass the point where all is sweet and the spray should be aft more and the bow will be up and the motors are working hard again !take particular notice of where the sweet place was when all was working well and shift the trim back to that place !! outboards are the same except its the motor trim thats important !!trims tabs will even the way the boat planes and correct the trim athwartships ( across ) if the boat is loaded uneven .
    Know your boat !! know what it likes !! each boat is a individual and almost has a soul of its own . hardly nobody gets to know there boat ,they just get push buttons , down with the lever and go !! then mumble this is wrong and thats wrong . :D
    Dont for get when you load up the boat for a day even the weight a little aft so you can trim better !! steering is the same its a personal thing . i made the choice and changed from cable to hydraulics and was the best move i ever made . its one finger controll all the way . i have big motor on a small boat so cant afford any slack anywhere at any time !
  6. rosbullterrier
    Joined: Feb 2005
    Posts: 83
    Likes: 2, Points: 8, Legacy Rep: 21
    Location: Cornwall, UK

    rosbullterrier Junior Member

    I appreciate your passion tunnels.
    I hope to learn the boat well; it's and my first test outing was yesterday after lengthy rebuild. It has that sneered at Stringer OMC system which hydraulic pumps the engine front up or down to trim. Well - it works ok and the trim gauges work!
    I now have been informed that low speed sterndrive wandering is very common, trimming might help. We shall see . . .

    IMP-ish those were very interesting threads.
    Last edited: Apr 16, 2012

  7. Frosty

    Frosty Previous Member

    As a car mech you will appreciate that toe in is for when the steering arm is under load zeros itself out when moving.

    With a boat you have the ability to adjust and set for speed at RPM.

    You might want to consider the Ackerman principle adopted in the automobile but seems to be totally ignored in the marine industry, not necessarily at my approval.
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