Steering problems on twin outdrives

[ballabunch]

I've scoured the forums for help on this subject, without much joy. The boat is a Fairline Fury with twin AQ130s driving VP 270 legs. Firstly, the steering is very heavy. I've greased all the points on the drives which helped a bit. How heavy should steering be (unassisted Morse)? With steering disconnected, outdrives swing fairly easily by hand and steering wheel is very light. Secondly, there is a lot of play in the wheel, which I think is stretched cable. Can you adjust this play (like the brakes on a bicycle) or is it a new cable? Thirdly, at speed she turns easily to port, but requires massive effort to starboard, so much so that you start to think she ain't going to come around. (She does have matching LH and RH props). How do you go about checking the toe-in, ie against which planes can I take a measurement? I've also read that you can adjust the trim tab on the outdrive to counter torque steer. I don't want to fiddle about until I have a clearer idea.

Any help would be appreciated.

<hr width=100% size=1>

 

[byron]

<font color=blue>Sounds to me like the cables need replacing. Maybe one of our more engineer orientated forumites can throw more light on the subject.

<hr width=100% size=1>http://www.alexander-advertising.co.uk

 

[duncan]

On the last part if you ave twin outdrives, and one is right handed and the other left, you shouldn't have any torque steer - or more precisely what you do have is balanced out by the two engines opposing each other. Only if they are trimming independently will one be able to influence over the other
Does the boat 'steer' straight with the two drives in the centre position? Has some power orientated bias got in or even do you have matching props (cue tr7v8!)?

<hr width=100% size=1>

 

[ballabunch]

I agree that they should balance each other out - hence my comment re: matched props - and, yes, these are indeed matched (ex Steel Dev). She does tend to steer slightly to port but not markedly so.

<hr width=100% size=1>

 

[oldgit]

My boat has 2 X 280 outdrives and I certainly could not describe the helm as "light".A slight drift to starboard is evident with the set up on my boat.It does become better when the boat is at speed.

<hr width=100% size=1>My little Princess/forums/images/icons/laugh.gifthe 33 of course.Shame its not just a bit bigger.

 

[duncan]

the only other observation I would make is that the difference in port / starboard doesn't rule out the cable / worm gear because they are doing pretty different things each way.
I replaced mine due to corrosion in the cable/sheath last year and from memory port was fine and starboard much harder.

<hr width=100% size=1>

 

[tico]

Yup.... It will take different efforts to port and starboard because altho the props are handed the engines are not so you get a differing gyroscopic moment. Most boats these days you wont notice coz they have power steering.
Many years ago, twin engines were made to run opposite hands to cancel this out.

BTW if u want I have a full set of power steering gear (pump, ram, linkages etc) to suit sunfury (same hull as a Fury) that came off two 290 legs. Offers??

I had to take it off coz the turbos on the diesels got in the way. Fitted hydraulic instead.

You will get wandering at low speed , its the same with all planing hulls. See the thread on here from a couple of weeks ago

Twin outdrives should toe-in a couple of degrees coz the props try to wind outwards in forward

<hr width=100% size=1>Been there, done that, got the oily T shirt

 

[ballabunch]

Tico - thanks for the info. As to the steering gear, I haven't a clue what it would be worth or whether the mountings would be suitable. I guess you had a couple of AQ140s in there before you changed to diesel. What prop sizes have you got, and what sort of performance difference have you found with the new engines?

Cheers,
Nick

<hr width=100% size=1>

 

[tico]

No... Had a couple of AQ171's. Great when everything is perfect, but so highly tuned , then went awry and then no power.

Put a pair of 140HP ford/Lancing diesels in last year... now goes really well ... best so far is 32 knots, start first time and 1/3 of running costs. Handling in big waves is better too with greater torque.

But fairly major engineering mods needed.!!

Original props were 14x19 on 290 legs ratio 2.15:1.



<hr width=100% size=1>Been there, done that, got the oily T shirt