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Old 05 May 2009, 09:44   #1
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RIB Pitching to left... tim tabs ?

Hi,

As some of you may remember I purchased a 5.8M Osprey Viper Max last month.

Can't say enough good things about it...however... I have one minor niggle (which i was warned about before I brought it)... basically when I'm going fast in large waves, the boat always wants to pitch to the left... not a major problem but it can become uncomfortable for the passenger after a time.

I think the engine was probably slightly miss fitted and maybe it wasnt 'off set' sufficiently.... I dont really fancy have the transome messed with, so what can I do ?

Its worth noting that the outboard doesnt have a little trim anode (not sure if thats exactly what they are called) I've been told this model (2005 Mercury Saltwater Optimax 150hp) Didn't come with them.

Could this be the problem ?

Also, would these automatic trim tabs eliminate the problem ? http://www.imsupplies.co.uk/product.php?productid=1426

Thanks for any help !
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Old 05 May 2009, 09:49   #2
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they transformed the handling of my sr4, have a look at the website below
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Old 05 May 2009, 09:56   #3
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Cheers Ollyit,

Did you have a similar problem to me ? Will it stop it jumping and landing to one side ?
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Old 05 May 2009, 10:25   #4
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yes I was over propped and had dolephins attached to the leg, dropped down to a 15" pitch, removied fins and added tabs - changed it massively, much better
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Old 05 May 2009, 11:31   #5
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Dont think think the trim anode on the opti is a problem - agree with waht you have been told - they never had them .
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Old 05 May 2009, 14:12   #6
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I would try everything you can before fitting tabs. I dont think using tabs to correct a lean is ideal.

Why don't you measure your offset to see if there is any? If not then you may want to look into getting the enging moved across. Its not as scary as it may seem as you could move the bolts down a couple of holes so they are not too close the originals and if you fill the original holes using some dowl and epoxy resin it should not weaken the transom.

Ideally you are looking for 1.5" but with that size engine on a 5.8 you may want to go to 2"
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Old 05 May 2009, 14:24   #7
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Quote:
Originally Posted by 1978SeaRider View Post

..I think the engine was probably slightly miss fitted ..
Didn't Manning rig that boat?
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Old 05 May 2009, 14:29   #8
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What offset and cav plate height has it been rigged at and how is the engine trimmed when you're running in big waves?
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Old 05 May 2009, 15:01   #9
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If it runs true in flat water it's not a trim issue. If it's bunging you to the left when the hull leaves the water it's a torque reaction off of the prop. I've experienced this big time with Phantom powerboats, but not with either of my ribs.

Maybe she's a bit over propped. The Phantoms were running big 27"P cleavers which grabbed great dollops of water with every blade. What prop are you running?

I agree, it is a bit tiresome when the boat lands cockeyed everytime it leaves the water.
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Old 05 May 2009, 17:01   #10
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If it runs true in flat water it's not a trim issue. If it's bunging you to the left when the hull leaves the water it's a torque reaction off of the prop. I've experienced this big time with Phantom powerboats, but not with either of my ribs.

Maybe she's a bit over propped. The Phantoms were running big 27"P cleavers which grabbed great dollops of water with every blade. What prop are you running?

I agree, it is a bit tiresome when the boat lands cockeyed everytime it leaves the water.
Exactly a RH prop will lean left as all the work is done on the down stroke. As you trim out the effect should be less. On my SACS 680 I just purchased a placed all the batteries etc on the right side of the boat to dampen this. This is common on single engine Offshore Race Boats.
Steve
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