Step hull issues

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
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jakedesnake
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Step hull issues

Post by jakedesnake » Tue Nov 18, 2014 8:21 am

I have a 12' Wilcox deckover with a gso480, 30 gallon gas tank.
Seems like it slightly rides the nose during cruise, rides great under power, but at about 75 it gets a porpoise and sometimes it'll power through it, but sometimes won't... I've tried to jack the motor up a quarter inch in the back, rides the nose more which doesn't make sense...
The bottom of boat looks perfect

Any ideas ?

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Deano
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Re: Step hull issues

Post by Deano » Tue Nov 18, 2014 10:43 am

Going a 1/4 of an inch is a HUGE adjustment.

By the sounds of it, I would think on that hull you were within a washer or two;
That is . . . IF such an adjustment would entirely correct the problem.

Is your ability to power through it sometimes, maybe related to the amount of fuel in the tank?
If so, that should give you a hint about your needed weight placement.
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jakedesnake
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Re: Step hull issues

Post by jakedesnake » Tue Nov 18, 2014 2:56 pm

Sometimes it'll power through, more depending on the depth of water... Not fuel
The crazy part is, I raised the rear of engine and it rode the nose worse... On a sled, it'll raise the nose also

It's a short boat so I was thinking maybe too much weight... But I see them with car motors

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stroked470
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Re: Step hull issues

Post by stroked470 » Tue Nov 18, 2014 3:13 pm

Raising the motor on a step also increases lift on the bow. I cant remember where the step is in reference to the transom on that Wilcox, I think its at either 6'-6" or 6'-8"...6'-6" being the better of the 2. The problem may be where your motor is positioned do to the length of that geared motor. Steps like the weight back absolutely as far as you can get it. Where is your fuel tank? It needs to be under the motor. I had a step with a supercharged geared motor and there were times if I had someone in the front seat it would try and ride on its nose as well. This is due to them having to sit in front of the step. Where is your drivers seat in reference to the step? I have seen a lot of older 6'-8" and 7' steps that have a crazy rear height on there motor, where you can actually see, like the prop is probably at 10-15 degrees in reference to the hull....so don't be afraid to go up with the motor, by the pics you sent me it dosnt look like you have went up far enough...I would go 3/8 bubble high on the motor providing you have the clearance in your cage

jakedesnake
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Re: Step hull issues

Post by jakedesnake » Tue Nov 18, 2014 3:30 pm

Don Davis built my stand, he said on a step, you build the engine level to the boat when the pad & step are sitting level.
Gas tank is directly under the motor. As far back as it can go.

I raised the back of the motor but rode the nose more... You would think it would raise the nose but it doesn't

It's not too bad, but annoying enough

jakedesnake
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Re: Step hull issues

Post by jakedesnake » Tue Nov 18, 2014 3:32 pm

It's a 6'6 step
Driver seat is right behind the step...
When I ride by myself, it'll start at 80...
With the cooler or someone in front... Sometimes it'll do it, somerimes it won't

Scarecrow
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Re: Step hull issues

Post by Scarecrow » Tue Nov 18, 2014 3:45 pm

Why in the world would you want to ride around at 80 mph? :shock: :rebel:

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John Fenner
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Re: Step hull issues

Post by John Fenner » Wed Nov 19, 2014 10:27 am

Go back to level, then drop it in the back a little then try it.
I never finish anyth,,,.

wildcard
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Re: Step hull issues

Post by wildcard » Wed Nov 19, 2014 8:51 pm

a lot of people run 80 mph in their mines but reality are 60mph boats a good set up Wilcox 6 6 step will go 96 + no problem most people don't know how to handle a 100 mph boat.you have to tune you're boat to you're specks it should run in the 90's no problem it is a bitch to get there :cheers:

wildcard
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Re: Step hull issues

Post by wildcard » Wed Nov 19, 2014 8:58 pm

a lot of people run 80 mph in their mines but reality are 60mph boats a good set up Wilcox 6 6 step will go 96 + no problem most people don't know how to handle a 100 mph boat.you have to tune you're boat to you're specks it should run in the 90's no problem it is a bitch to get there :cheers: a fast boat will handle different with conditions ,water,wind, temperature, just like raceing call waterthunder,he knows it all on airboats on southern airboat :stirpot:

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Waterthunder
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Re: Step hull issues

Post by Waterthunder » Thu Nov 20, 2014 9:47 am

I don't think I have ever seen a step hull where the owner didn't tell me the boat would run at least 90mph.
THE PROOF IS IN THE PROP!

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Tra
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Re: Step hull issues

Post by Tra » Thu Nov 20, 2014 11:02 am

whats wrong with a little chatter desnake? thats when you know your partying
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John Fenner
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Re: Step hull issues

Post by John Fenner » Thu Nov 20, 2014 12:59 pm

The framework for the decking could have altered the bottom enough to make it chatter.
I never finish anyth,,,.

slow ride $$$
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Re: Step hull issues

Post by slow ride $$$ » Thu Nov 20, 2014 8:12 pm

i have had at least 10 steps ,and 2 were wilcox hulls .and all had a chatter at 75-85 mph but it should run thru it .

southernrican
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Re: Step hull issues

Post by southernrican » Thu Nov 20, 2014 8:51 pm

I'd say it's normal. Mine chatters at around 80 n I'm on a step.
11'7" freedom craft step hull
Lycoming geared supercharged GSO 480
10 blade saber running 14 degrees.[/color]

Uhairball
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Re: Step hull issues

Post by Uhairball » Thu Nov 20, 2014 10:22 pm

Kind of reminds me of a coworker I had up in Pittsburgh. He rode a Suzuki crotch rocket to work. He lived over an hour from work, and was always running late, therefore he was always WFO. One time he told me that his front wheel started to wobble at 110mph, but at 120 it smoothed back out. My reply was, if the front wheel starts to wobble at 110mph, why would you want to go faster?
Maybe I'm just a chicken....

T-REX
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Re: Step hull issues

Post by T-REX » Fri Nov 21, 2014 11:15 pm

It's never the speed that gets you killed-
It's how fast you stop..... 8)

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