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Old 21 October 2008, 17:53   #1
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Country: USA
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Boat name: Hammerhead 13'3"
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Engine: Suzuki 30HP 4stroke
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Inflatable Tunnel Cat Speed wobbles

Hello all,

I have just upgraded my outboard motor on my DUX Hammerhead from a 15 hp to a 30 HP. I just took it out yesterday with my new outboard for some test runs. I installed the Suzuki DF30 30HP 4stroke. I did my test runs in Oceanside, CA in the harbor and out in the open ocean. A comfortable and easy handling of the boat likes to go at about 15mph. When I did run OWT I got up to 24mph and climbing pretty quickly, but the boat also liked to skip around the surface of the water and the tiller was moving left and right really quickly. I would compare it to speed wobbles going down a hill really fast on a skateboard or bicycle. Now, it was only myself in the boat. All the weight was in the back; the 200+ lb outboard motor, a 6 gallon tank that was half filled, and myself. I would like to ask anyone outhere with experience in these boats at highspeed. Can you please share setups, aftermarket accessories to tame down the handling; steering dampeners and such. Here are a few pics of the setup. Thanks for your help in advance.





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Old 21 October 2008, 18:13   #2
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Get a longer tiller arm - you will sit further forward and have more leverage.

I think there is an adjustment to tighten up the steering swivel. Also removing the prop guard may help.
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Old 21 October 2008, 20:57   #3
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Is that a long shaft engine??? Its hard to tell from your pics - you need a short shaft one for that boat- it certanly needs to be raised up on the transom by a fair bit. Yes an extended tiller will help but it wont stop the speed wobbles- you really need a steering damper like this used on the thundercats http://www.leisureshopdirect.com/mar...al_Extras.aspx

and a bracket to mount one end onto the top of the transom and mount the other end on the tiller near to the cowling- you will get a super smooth speed run then.
I use this setup on my boat with a 50hp-without it it is a real handfull keeping it in a straight line especially when going over 40mph.
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Old 21 October 2008, 23:40   #4
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Country: USA
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Quote:
Originally Posted by Easyrider View Post
Is that a long shaft engine??? Its hard to tell from your pics - you need a short shaft one for that boat- it certanly needs to be raised up on the transom by a fair bit. Yes an extended tiller will help but it wont stop the speed wobbles- you really need a steering damper like this used on the thundercats http://www.leisureshopdirect.com/mar...al_Extras.aspx

and a bracket to mount one end onto the top of the transom and mount the other end on the tiller near to the cowling- you will get a super smooth speed run then.
I use this setup on my boat with a 50hp-without it it is a real handfull keeping it in a straight line especially when going over 40mph.

Thanks for the responses. Yes, my motor is the long shaft.
do you have any pics of your 50 with the dampener installed?

thanks,

Jeff
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Old 22 October 2008, 06:23   #5
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Quote:
Originally Posted by Easyrider View Post
Is that a long shaft engine??? Its hard to tell from your pics - you need a short shaft one for that boat- it certanly needs to be raised up on the transom by a fair bit. Yes an extended tiller will help but it wont stop the speed wobbles- you really need a steering damper like this used on the thundercats http://www.leisureshopdirect.com/mar...al_Extras.aspx

and a bracket to mount one end onto the top of the transom and mount the other end on the tiller near to the cowling- you will get a super smooth speed run then.
I use this setup on my boat with a 50hp-without it it is a real handfull keeping it in a straight line especially when going over 40mph.
I thought that engine looked very low. The Dux website states a 15"/20" shaft for that model which as far as I can tell would mean a short or long shaft
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Old 22 October 2008, 09:05   #6
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Why not ask the guy sat on the pontoon in the first picture. He looks like he might have an opinion
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Old 22 October 2008, 12:04   #7
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Why not ask the guy sat on the pontoon in the first picture. He looks like he might have an opinion
He does look a bit long in the face doesnt he

Jeff-As soon as ive worked out how to post pics ill put them on here
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Old 22 October 2008, 12:39   #8
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Here we go-not sure if its going to work + pic quality isnt great.
The last pic is to show you what level my prop/gearbox is in relation to the hijackers.
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Old 22 October 2008, 13:08   #9
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Thank you so much for posting the pics. That helps a great deal.

Very nice setup you have.

JS
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Old 22 October 2008, 13:28   #10
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Originally Posted by Easyrider View Post
Here we go-not sure if its going to work + pic quality isnt great.
The last pic is to show you what level my prop/gearbox is in relation to the hijackers.
Hola Easy

Just an issue as I'm only a sibber, what is the purpose of the steering dampeners for, to put more friction on the tiller, not to be so light moving side ways ? Work with Tohatsu engines, most of them are factory delivered with steering friction a bit light, adjust all of them by means of a + 5 CW adjustment on the steering friction nut. Now much better steering performance than before. Can drop the steering handle with no prob. Why don't you just adjust the nut a bit and test.

Happy Sibbing
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