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Old 15 August 2004, 16:36   #11
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Cheers guys, and thanks Jono.

I haven't had the chance to really check everything out yet, but it seems to be worse on a starboard turn. I agree with the thoughts about the angle causing additional 'weight'. Though I'm not sure it's to do with the trim tab as I understand this is there to counteract any tendancy to veer off course due to engine torque.

Presumably hydraulic steering is not power assisted, but rather relies on more turns of the steering wheel and the benefits of fluid to help move the engine. Am I right?
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Old 15 August 2004, 16:47   #12
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Hi Erin,

Have a look at this: http://www.seastarsteering.com/OVERV.../oviewF3.htm&3

I think some inboards, and the new Mercury Verado have a PAS system.

HTH!
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Old 15 August 2004, 17:24   #13
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I'd still be pretty sure that it's a trim tab problem.

You are correct that the trim tab corrects the torque effect of the prop. This effect will be far more pronounced in a turn and even more so when power is applied.

I doubt if the weight of the engine while banked in a turn would be a significant factor as the forward motion of the hull through the water causing a powerful water flow against the main keel fin would negate this and tend to straighten the engine if anything.


Power steering works as follows...You turn the wheel which works a small pump which pms the fluid into a ram that turns the engine...just like a hydraulic jack. The normal cross over threshold for PAS from cable steering on a RIB would normally be around 150 hp. As I said we have several 6.5 m RIBs with such engines which are finger lght to drive in all conditions with cable steering

Best wishes,

Stuart
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Old 15 August 2004, 17:41   #14
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Think about the geometry of the steering linkages at full lock.
Combined with a maladjusted or missing torque tab and lots of prop torque .....
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Old 16 August 2004, 03:24   #15
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Erin

how do you like your 6m prosport?
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Old 16 August 2004, 03:41   #16
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Quote:
Originally Posted by Powerboat
Power steering works as follows...You turn the wheel which works a small pump which pms the fluid into a ram that turns the engine...just like a hydraulic jack.

Thanks for that, I've always wondered! Now I don't suppose you know how to suck eggs, me granny is having a real problem!!!!
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Old 16 August 2004, 04:10   #17
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Guys,

In addition to all the suggestions posted here, I believe that the leverage generated by the steering linkage system is less when the greasy "piston" (what is the technical term?!) is inserted all the way into the outer cable and more when extended all the way out. I could be wrong, but I have learnt not to leave it in the "non-extended" position when left over winter because there is less leverage available to release it should it get seized.

So, depending on which side you have the cable coming out of your engine, this lack of leverage could either add to the prop torque problem or improve it. I too have experienced heavy steering on a rib with a yam 90hp on the back.

Somebody please correct me if i'm wrong! Sorry its all a bit non-understandable!

Tim
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Old 16 August 2004, 10:40   #18
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Quote:
Originally Posted by Jono Garton
Erin
how do you like your 6m prosport?
Probably not much considering that so far he's reported chine walking and steering problems.

My guess is that the routing of the cable has got too tight a turn up to the engine. Either that or a cheap and nasty steering kit. A quality steering head and cable kit should give any engine up to 115hp finger light steering.

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Old 16 August 2004, 10:51   #19
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if its chining, put some chain in the nose!
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Old 16 August 2004, 14:52   #20
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Erin, what speed are you talking about. I ask this because you've mentioned;

when I’m manoeuvering...
When I go into a tight turn...
It’s basically when trying to come out of turn...

If you're at manoeuvring speed that would be quite different to, say, cruising speed.
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