Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

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doodle

Cadet
Joined
May 20, 2010
Messages
13
I have a 16 ft "Ski Barge" it's the type of boat for fishing on rivers etc. It needs to go "on plane" in order for the boat to go faster. However, when I wake-board using a pylon pole it doesn't plane and goes at a slower speed and I am unable to get up at all even though I only need to go at a speed of 18-20 mph. The motor is a 70 hp.

Why does this occur? Is it because my pylon pole is in the center of the boat?? Do I need to move the pylon pole further out near the head? Or should I just get a tow harness?? Would that work better?

What do you guys think? Are ski Barge just not capable of using it for wake-boarding???
 
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craze1cars

Lieutenant Commander
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Dec 26, 2004
Messages
1,822
Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

This has nothing to do with your pylon or rope attachment. It's just a HP thing. I'm not sure how heavy you are, or how heavy your boat is, but it all comes into the equation. If you're a big guy that can make a big difference.

Also don't know how your boat is propped, how fast it normally planes, how your weight on board is distributed, or what your max RPMS normally are at top speed when you use this boat. I also don't know the state of tune of your motor. You may simply be overpropped and need to go down a couple inches in pitch for wakeboarding.

Lots of questions, but generally speaking, buying a smaller pitch prop is the most common solution for underpowered boats to help them accellerate faster and plane easier.
 
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doodle

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May 20, 2010
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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

craze1cars said:
This has nothing to do with your pylon or rope attachment. It's just a HP thing. I'm not sure how heavy you are, or how heavy your boat is, but it all comes into the equation. If you're a big guy that can make a big difference.

Also don't know how your boat is propped, how fast it normally planes, how your weight on board is distributed, or what your max RPMS normally are at top speed when you use this boat. I also don't know the state of tune of your motor. You may simply be overpropped and need to go down a couple inches in pitch for wakeboarding.

Lots of questions, but generally speaking, buying a smaller pitch prop is the most common solution for underpowered boats to help them accellerate faster and plane easier.
Click to expand...

I'm 165 lb. The boat is a outboard motor and it usually goes around 30-35 mph for sure. It planes usually around 10-15 mph I think because we don't even need it to go half till it planes.
 
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craze1cars

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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

What are your RPM's when the boat is going full speed?

And what year/make/model is the motor? Do you know what your target RPM for max HP is supposed to be for that motor?
 
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doodle

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May 20, 2010
Messages
13
Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

craze1cars said:
What are your RPM's when the boat is going full speed?

And what year/make/model is the motor? Do you know what your target RPM for max HP is supposed to be for that motor?
Click to expand...

I really have no idea... I know on the prop it states 13-1/4X 17 and someone told me on the forum that that is recommended and should work. The boat is a 16 feet and the moto is a johnson 70 hp 1983. It's still pretty good since it starts when I start the key and has not had any problem. I'm pretty sure I go at least 30-35+ mph when I'm at full throttle.
 
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bigpoppakdog

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Jul 9, 2008
Messages
437
Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

Had this issue with a boat I had a few years ago. Solution was to move everybody up to the front until boat planed, then moved them to the back to make a bigger wake.
 
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craze1cars

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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

doodle said:
I really have no idea... I know on the prop it states 13-1/4X 17 and someone told me on the forum that that is recommended and should work. The boat is a 16 feet and the moto is a johnson 70 hp 1983. It's still pretty good since it starts when I start the key and has not had any problem. I'm pretty sure I go at least 30-35+ mph when I'm at full throttle.
Click to expand...

If you don't know your RPM, then you have no idea whether or not you are actually making 70 HP at the prop. For example, if you're over-propped and under-revving, you may only be generating 55 hp or so. You really need to hook up a temporary shop tach or something and find out where you're at.

That motor is supposed to be spinning between 5,000 and 6,000 rpm at top speed for max power. And for watersports and maximum hole-shot, you will want to be as close to 6,000 as possible. If you're below 5,500, which I suspect you are, then your 17 pitch prop is too big for watersports.

The last 70 hp 16 foot aluminum boat I skiied behind frequently had a 15 pitch prop put on for watersports, and then we put on a 17 pitch prop for general boating use to prevent over-revving at top speed. I wouldn't be surprised if you need to do the same.

I totally agree with previous poster about moving as much weight as possible to the front for take-off.
 
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bigpoppakdog

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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

I had a tri hull boat with a merc. on it. Can't remember for sure but maybe an 85 hp or something like that. With anybody sitting in the boat it would not plane trying to pull me up. I'm 205 lbs, so not small, but not the biggest either. I had two people move up to the bow and it planed almost immediately. Then moved them to the back to make the wake a little deeper. I since got a different boat with a 115 hp evinrude. This planes out to about 400lbs on a tube. I pulled 4 people on a gigantic tube and she struggled to plane. Again, moved people up to the front and I did get it to plane. Didn't do that too often as it was pretty hard on the motor.
 
skibrain

skibrain

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Jun 17, 2004
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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

The tower is a high enough tow point that it acts like a big lever on your light boat. The pull from the rider doesn't allow the bow to stay down and the boat get on plane.

I had a 16' boat with 120 outboard and a pylon that was high enough to clear the motor (so not nearly as tall as a wakeboard tower or sky-high pylon). Yes, dropping to a 17" pitch would have given me more hole shot, but the time to plane pulling up my 200# buddy using the pylon was much slower than when the ski rope was attached low on the transom eye.

Weight forward in the boat, or try it without the high tow point.
I'm assuming you have your trim down all the way if you have power trim and tilt. If not, you may consider changing the trim pin to tuck the motor closer to the transom. Less top speed this way, but better hole shot or lower bow running at wakeboard speed.
 
metriccrescentwrench

metriccrescentwrench

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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

I've got a couple of thoughts on this.

First, as a reference point for your prop, I've got a 14-1/2 ft boat with a Johnson 90 and a 13-1/4 X 17 prop, sounds like it's either the same prop or at least very close to the one you have. That prop is just right for my boat, which is a little bit lighter and with a little bit more power than your boat. So I'd guess that you'd see good results by switching to a prop with 15 inch pitch.

Also, rider technique has a lot to do with how well the boat will pull you up. When my son first transitioned from skis to a wakeboard my boat had a heck of a time getting him up. I'd be at full throttle and the boat was almost sitting still struggling to drag him along behind it. After he got a little better he could pop right out of the water, just like on skis. Now I'm using about 2/3 throttle and it only takes a couple of seconds for him to get up and I have to start backing off the throttle to maintain speed.
 
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bigpoppakdog

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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

Yes, excellent point on rider technique. I have wakeboarded behind a 50hp motor because I can pop myself out of the water on takeoff. When my kids were learning, one would take more power to get out of the water than the other. They weighed the same. Once you learn how to stand up and pop yourself out of the water, you can wakeboard behind pretty much anything.
 
Challenger84

Challenger84

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May 9, 2010
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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

I also have a 83' 70hp Johnson on a 16' open bow rider.
My prop size is also 13-1/4x 17
I have an extra prop that is 13-3/4x 15.
My boat weighs in at 750lbs.

At WOT I can get the boat to go 42mph.
That's just me and about 3 gallons of fuel.
The Johnson really gets my boat on plane in a big hurry. With the boat at max capacity she only goes 28-30mph.(5 adults and fishing gear and about 11 gallons of fuel and a cooler).
I'm assuming that it has enough power to pull my tube.
Well I just got the boat and a tube and was wondering if it was powerful enough to pull a tuber?
Should I go ahead and change my prop before I hit the lake with the extra one that I have?
 
Challenger84

Challenger84

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May 9, 2010
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341
Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

Bump?
 
skibrain

skibrain

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Jun 17, 2004
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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

I would assume you are not tubing with 5 adults and gear in the boat (+ 850# ?)
Leave on the 17" prop. and throw the 15" in the trunk.

The 17 should work fine as long as you aren't too loaded up.
 
Challenger84

Challenger84

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May 9, 2010
Messages
341
Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

Thanks for the advice.
I'll just do a trail run and se what happens.
If not I'll just pull the boat back up and change the prop.
Happy boating!
 
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sethjon

Senior Chief Petty Officer
Joined
Jun 8, 2010
Messages
692
Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

One thing nobody mentioned about the prop is how many fins? 4 will work great.
 
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wjd

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Jun 13, 2010
Messages
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Re: Wakeboarding... Why does my boat not have power when I wakeboard?!?!?!

I had the same problem and my timing was slightly off and it wouldnt let my boat get up the right amount of HP.
 
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