Heavy steering on full lock!

[Erin]

Just got my new rib last week and have been out having a play this afternoon trying to get the hang of it and find out how much fun I can have

However, I've encountered a bit of a problem which worries me slightly. When I go into a tight turn the steering becomes extremely heavy and I have to use both hands to straighten the wheel up. Now this may not seem like much of a problem, but it does mean I have to take my hand off the throttle which I'm not too fond of doing when I'm manoeuvering. It may just be due to the weight of the engine, the torque, the tightness of the turn etc, but is there something wrong with the steering, or is it something I'll have to put up with unless I go hydraulic?

The boats a 6m with Suzuki 90 hanging off the back... a heavy lump I know.

[Tim M]

I have the same problem. I think it's a standard sort of problem.

[Hightower]

Is it as heavy when moved from lock to lock when stationary?

I suspect that it might be the torque from the prop that might make the steering heavy at the extremes of lock. Only a thought, hope it helps.

Andy

[Tim M]

I suspect that it might be the torque from the prop that might make the steering heavy at the extremes of lock.

Hence it gets worse at higher revs....

[Andy]

Is the boat new? If its not then read on .... if it is new then this may not help you.

Try getting a grease gun and pump some into the nipples that lube the support shaft (not sure whats the techy term for it). The engine turns within it. This can bind when under load if its not greased regluarly.

It could also be the cable are getting on a little and binding. Turning tight corners puts lots of load on the steering system and can often shows up problems.

[Erin]

The whole lot is brand new, so it really shouldn't be a lack of grease. It's basically when trying to come out of turn that it gets really stiff. I suppose I'm trying to change the direction of the whole boat which must weigh close on half a ton (plus passengers) with just a little steering wheel. It's fine going into the turn, it's coming out that suddenly takes me by surprise

[Powerboat]

There will be a little trim tab (vertical fin) on the anti cavitation plate behind the prop. It will be unpainted zinc as it also doubles as a sacrificial anode.

By moving this slightly it will take the pull out of your steering.

If confused as to which way to adjust it. Look at the engine when the boat is sitting on the trailer. If your boat is pulling to port move the trim tab out further to port and vice versa for starboard.

You should not have to move it more than 30 degrees from straight. 10 to 15 degrees would be normal.

Be sure to tighten it properly before going back on the water !!

Here at the Powerboat School we find that this is a common problem with boats bought off of casual agents who have not set up the boat properly prior to delivery as opposed to boats bought directly from the manufacturers or an approved agent.

Of course my final advice would be to go out and book an RYA ( UK ) or ISA ( Ireland) Level 2 Powerboat Handling course which will teach you all this and much much more for the price of a sailing jacket !

Feel free to email me off list for further help or a more detailed reply ( Dashing now for lunch !!!)

Kind regards,

Stuart

[Powerboat]

Just as an aside , we have a wide range of RIBs here from 60 hp to 130 hp . All can be driven (as they should ! ) with one hand on the throttle at all times and one hand on the wheel with easy and finger light operation of one handed steering up to full throttle.

So this is not a problem you should accept or consider normal !

Most modern engines come with the anode / trim tab already pre curved like a wing to enable a slight to counter the torque effect of the prob at high power..

Best wishes,

Stuart

[Hightower]

There could be another reson for it being heavy during a very tight turn. As the RIB and outboard are angled (possibly 20/30 deg) in relationship to gravity whilst executing your turn, you have to effectively lift a percentage of the weight of the whole engine to get the boat to staighten out, it might not be too much of a problem for hydraulic steering but for cable type I guess it could have an influence!

This might be another reason steering feels heavy when trying to straighten her up.

But it's something most of us "cable" RIBsters have to live with and quite normal I think.

Andy

[Jono Garton]

i have the same problem with my pro sports, but only when the weathers hot!!! How strange is this?

Belive Ian as the same problem but hes got a 250hp on cable steering.

[Erin]

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?

[Richard B]

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!

[Powerboat]

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

[Matt]

Think about the geometry of the steering linkages at full lock.
Combined with a maladjusted or missing torque tab and lots of prop torque .....

[Jono Garton]

Erin

how do you like your 6m prosport?

[Dirk Diggler]

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!!!!

[slimtim]

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

[DM]

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.

DM.

[Jono Garton]

if its chining, put some chain in the nose!

[jwalker]

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.