Help Holding Speed with a I/O

(lume1) · (lume1) **Join Date: Mar 2005** 05-30-2006, 5:59 AM

I can't hold the speed with my I/O. If i reach a good speed it seems to accelerate by itself so i have to slow down a bit...but it keeps slowing down so i can't keep the right speed.
anyone????

(gmarkham1) · (gmarkham1) **Join Date: Sep 2003** 05-30-2006, 6:20 AM

besides lots of practice,
a lower pitch prop, preferably at least a 4 blade aluminum(most bang for your buck), some type of foil on your outdrive, and last but not least perfectpass!

(psudy) · (psudy) **Join Date: Dec 2003** 05-30-2006, 6:27 AM

Thats part of an IO. You have to practice. Listen to the engine. You should be able to hear it reving up or down and be able to make adjustments as needed.

bamer001 05-30-2006, 9:22 AM

I had the same problem so I put Nauticus smart tabs($200) and a high five prop ($600) on my i/o last year. I put the tabs on first so I could observe the changes, then I selected a 21" pitch for the prop. Time to plane was around 5-6s before and 3-4 afterwards. My minimum planing speed went from 18 to 15 mph. I think you biggest gain will be to start with smart tabs and get your minimum planing speed down. My wife can hold 18-19 pulling me with ease, but I still have work a little at 15-16 pulling her. What speed are you tring to hold, and are you pulling someone?

(lume1) · (lume1) **Join Date: Mar 2005** 05-30-2006, 9:29 AM

I don´t know the speed, but i am trying to hold like
2900 rpm but it´s very difficult

bamer001 05-30-2006, 9:34 AM

All of the results I quoted above are with the smart tabs only. I have not tested it with the high five, but I know its even better now.

(lume1) · (lume1) **Join Date: Mar 2005** 05-30-2006, 9:43 AM

Sorry for my ignorance but I speak spanish and i dont understand some things.

smart tabs??

bamer001 05-30-2006, 9:46 AM

Here's a site that explains what smart tabs are?
http://www.boatownersworld.com/smartabs/smart_tabs.htm

(psudy) · (psudy) **Join Date: Dec 2003** 05-30-2006, 10:08 AM

Why don't you just by a Perfect Pass system?

(lume1) · (lume1) **Join Date: Mar 2005** 05-30-2006, 10:11 AM

Because i live in URUGUAY and there is no such thing as perfect pass in here and ordering it would be too expensive

(rodmcinnis) · (rodmcinnis) **Join Date: Sep 2002** 05-30-2006, 10:22 AM

There is a problem of holding speed, especially at the speed you want for wakeboarding for any boat. The problem is worse on an I/O than it is on an inboard but even a wakeboard boat suffers from this.

The basic problem is that wakeboarding speeds are right at the spot where the boat's hull dynamics are changing. As the boat comes up on plane the amount of power necessary to hold the speed reduces. The simple fact is that there is no stable point where a given throttle setting will hold a constant speed.

To make matters worse you can't watch the tachometer and hold constant engine speed as just the changes in prop effeciency will create dramatic speed variations.

The only thing you can do is watch the speedometer very closely and constantly adjust. It is not easy but it can be done.

You can help the situation by changing how the boat rides in the water at the speed you want to go. If you can make the boat level out it will be a lot more stable.

There are a few things you can do to change the trim of the boat. One way is to install "trim tabs" on the transom of the boat. Simple ones are just bolted on and you adjust the angle of the tabs for one purpose. You can buy adjustable trim tabs that allow you to change the angle as you drive.

Another way to adjust the trim of the boat is to put more weight forward to help bring the bow down.

bamer001 05-30-2006, 10:34 AM

"If you can make the boat level out it will be a lot more stable." That is what the smart tabs do, but they are automatically adjusted via a gas cylinder. Check out the web site above

(mjmurphy53711)

Learn to "bump" the throttle. I/o's throttles tend to be too abrupt in their response, one "step" up is usually too much.

Your accelaration is due to the way an I/O planes out, as it planes it will accelerate.

Try this.....

Pull your rider up and accelerate hard bringing her up to plane, next, throttle back until you are one step back from where you want to be. Give her one slight "bump" up and you should be good to go.

I know this sounds funky, but it works....I spent a few years on a huge I/O with a sticky throttle, and soon enough your wrist will develop some memory.

tweetdriver 06-04-2006, 8:37 AM

That last tip sounds about right. I really accelerate hard until the boat planes and then I bump it back to a familiar rpm "sound" and then double check speedometer. After that, a little nudge back and forth holds the speed. Takes some practice, but you get used to it. Anyone know/have perfect-pass on I/O's???