Inflatable Tunnel Cat Speed wobbles

[Jeff Salinas]

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.

 

[deejaycee_2000]

Re: Inflatable Tunnel Cat Speed wobbles

Hi Jeff

Very nice, looks good ..... first of all ... lose the prop guard, it slows you down too much .... I would bolt the motor on (from what I can see it is not bolted on) ... I would also lift the motor up a bit so that the center of the prop is in line with the centre of the high jackers (the center of the valves on the bottom little pontoons) .... you would need to fit a steering damper, you can spend money and get a seastar steering damper for your motor, or go the cheap route and get yourself a mercedes steering damper from any mercedes part center .... if you are going to be driving alone on the boat tie your fuel tank down in the front on the opposite side of where you sit .... I would also suggest getting footstraps that you can glue on so you do not fly out ..... have fun

 

[tashasdaddy]

Re: Inflatable Tunnel Cat Speed wobbles

Dang, DJC, talking about safety equipment.

 

[SnappingTurtle]

Re: Inflatable Tunnel Cat Speed wobbles

Great looking boat!

If you don't have a Mercedes dealer near you, check out the local performance motorcycle shops. The also have dampers that work really well on smaller outboards, and they are reasonable in price.

Dang, DJC, talking about safety equipment.

He! He! He! Whats the world coming too?

 

[Jeff Salinas]

Re: Inflatable Tunnel Cat Speed wobbles

Hi,

Thanks guys' so much for the quick and prompt responses. I appreciate it very much.

It's hard to see in the photos but the motor is bolted on. I guess the first thing I will do is lose the prop guard. When I purchased the motore it already had that contraption on there, so I just went with it. Then I found out the manufacturer of them here;

http://www.propguardmarine.com/how.html


Is there any truth to this?

anyhow, I like the alternative route on steering dampeners; Mercedes or motorcycle steering dampeners. Does anyone have any pictures of there steering dampeners installed on their outboard. I would like to have an idea on how I would be able fit it in and if I would have to fabricate anything for the install.

Thanks again guys'

Jeff

 

[bayman]

Re: Inflatable Tunnel Cat Speed wobbles

As for the prop guards...someone once said, "In God we trust, all the rest - show us your data!". I've never seen any data that showed a boat to be more efficient based on a prop guard. If that were the case then you would see them on on almost every boat. If a boat were going super slow then maybe there is a chance at more efficiency...in my mind anyway. Mercury Marine did many tests on these years ago and one of their conclusions was that prop guards have the possibility of making things more dangerous in certain cases. If an appendage gets stuck in there it's much worse than if an appendage was run by quickly. Anyway, one does need to be careful with props, with or without a prop guard.

 

[kandil]

Re: Inflatable Tunnel Cat Speed wobbles

Hi this a nice boat is that a cut? I see that you have cut on the lower part off the PVC holding the high jackers to the boat if so it could be why you wobbles batch it and see what happen. good luck

 

[Jeff Salinas]

Re: Inflatable Tunnel Cat Speed wobbles

Hi this a nice boat is that a cut? I see that you have cut on the lower part off the PVC holding the high jackers to the boat if so it could be why you wobbles batch it and see what happen. good luck

No cuts around the hijackers. I guess DUX designed the boat that way to have them exposed. I would think it's an easier way to have them exposed so you can drain the water out more easily. I don't think it would be neccessary to have them enclosed.

JS

 

[kandil]

Re: Inflatable Tunnel Cat Speed wobbles

on the side not the rear If you don't get the footstraps make sure you snap the kill switch to you at all time!!

 

[deejaycee_2000]

Re: Inflatable Tunnel Cat Speed wobbles

the prop guard cause drag, the more drag the slower it goes, for instance what will go through butter faster, a sharp knife or a spoon .....

it is true, a prop guard can cause more damage than without it, the only ever death in our racing was with a prop guard .....

anyway, see the pics on my steering dampener ....

 

[kandil]

Re: Inflatable Tunnel Cat Speed wobbles

Hi deejaycee_2000 nice setup I love this tiler handel where can you get one? and are they universal? thanks

 

[Jeff Salinas]

Re: Inflatable Tunnel Cat Speed wobbles

That is one nice setup you got there deejaycee_2000. Thanks for sharing.

Jeff

 

[deejaycee_2000]

Re: Inflatable Tunnel Cat Speed wobbles

thanx guys, the tiller extension that I have was custom made by the guy who strengthened my transom bracket and engine mounts .... but you can buy ones .... see link http://www.aquariusinflatables.co.za/Accessories.htm

 

[kandil]

Re: Inflatable Tunnel Cat Speed wobbles

Hi Jeff I went out today in my cat and I had the same issue wobbling I removed the prop guard of my Tohatsu 25hp and that fixed the problem like deejaycee said lose the guard. did you check the cut on the right side?

 

[Jeff Salinas]

Re: Inflatable Tunnel Cat Speed wobbles

Hi Everyone,



Thank you all for chiming in and sharing your tips and experience. Since my first test ride with the motor, I have then did another test drive without the prop gaurd and this time with another person to help ballast it out. I have also tightened the friction clamp on the tiller. My results are much better but can also be improved more. It it was much more easier to control and handle the boat this time. I can go WOT now in open water. And I got a top speed of 26mph via gps. But I did get water over the transom. My motor is too deep. With the trim set to the 3rd notch up the water over transom does lesson a bit but I get some serious bow rise before planing out. I think next what I'm going to do is raise the motor. The most I can raise it up using the holes on the outboard to bolt on would be 2". would still need a shim to fill in the gap.







So I raised my motor by 2" using the variable thru holes of the outboard. I drilled through the transom and bolted it with stainless steel 1/2" bolts. It seems sturdy, but my main concern is the empty space as seen in the pics. I haven't rode it like this, I just wanted to get peoples' opinions on what they think if this will work.



Thanks,



Jeff

 

[deejaycee_2000]

Re: Inflatable Tunnel Cat Speed wobbles

Hi Jeff, it actually looks like you can raise it even more .... but try it like that for now .... you do not need to worry about the gap, as long as you torqued those bolts really tightly and also have lock nuts on there ..... you can put a piece of perspex in there or even a piece of wood if you really want, I use perspex but only to basically keep the gap while I tighten the bolts, cause it is hard to do by yourself .....

 

[kandil]

Re: Inflatable Tunnel Cat Speed wobbles

Hi man you can use a piece of square aluminum tubing for a chem. and is this a long shaft?
it looks kind of long
PS
How do you upload this large photos?

 

[Jeff Salinas]

Re: Inflatable Tunnel Cat Speed wobbles

deejaycee_2000,

Once again thank you so much for your insight and your valuable information as always. What you offer here to many is always appreciatted, and I'd just like to say thank you.

I am going to run her as shown in the pics, It needed your blessing first.

Kandil,

As for posting the large pics on the thread;

First you need to find a site to upload your pics to. I use Photobucket.com
After my pics are hosted from them, I then right click on the pic and copy the address(URL) under properties. You then just paste it between these tags;


"

"


Once the thread is submitted the pics will show up when viewed.


BTW, don't use the quotes.


JS