USE THE SYSTEMS ON YOUR BOAT TO /SAVE FUEL/ GAIN SPEED

 

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PERFORMANCE/ HANDLING/ SPEED/ FUEL BURN IMPROVED JUST BY YOUR CONTROLS

 

INBOARD OUTBOARD (I/O) / OUTBOARD

Is it possible to affect all four of these things with a simple lesson in operating the trim control and trim tabs with a boat powered with an  I/O or Outboard?  Yes it is! The changes in the boats performance are greatly affected by these two hull control systems on your boat. A lot of boaters do not realize how these two trim systems can make or break the way your boat gets on plane and handles. The effects that poor use of these systems can have are increase fuel burn and the way your boat responds to steering input and speed. Here is how it works:

Trim Control; This is the button usually located on the shifter that you use to manipulate the position of the drive up or down. The trim button has two uses: One it allows you to trim the drive up or down during normal operation. Once you have trimmed the drive all the way down you should only be able to trim it part way back up. The drive should stop on its own on the way up, this is controlled by the trim limiter. This protects the U joints on the drive shaft from being damaged by having to much angle on the drive. (If you can trim the drive up and down thru the whole range without the limiter stopping you. Visit a mechanic and have the trim limiter repaired. There is a real danger of blowing the U joints and belows apart and sinking the boat) If you start with the drive all the way down as a starting point, the drive is actually not straight up and down it is now in a position were the prop is pointed almost right at the bow of your boat. When you operate a boat this way ( TRIM ALL THE WAY DOWN) you are pushing the bow down into the water. So as you power up and try to plane the push from the drive is fighting the boats bow wanting to rise. If you have DOL FINS or cavitation plate extenders this is an even worse bow down push. This drive position is ideal for low speed manoeuvreing only!

 

 

 

Once you are free of the dock give the trim button a quick bump or two up. this will place the drive in a more vertical position and allow the bow to run free. Steering at above idle speeds will become more responsive.

 

 

There are a couple of things you need to understand at this point:  Above the prop on the drive is a large flat plate. This is called the cavitation plate when you are on plane this plate is at the water line. The plate rides on top of the water. The drive is very much like a set of trim tabs it can control the rise or fall of the bow when you are on plane. The trim tabs and the drive can fight each other when the hull is trying to getting on plane and certainly once the hull is on plane.
 

 

Before you attempt to get the hull to plane! If you have trim tabs make sure they are in the up position. BOW UP all the way. This will allow the hull to be unimpeded by the trim tabs. With the drive just slightly up from the lowest position. Move up thru the throttle range the bow should rise and then begin to fall within seconds. This doesn't require jamming the throttle thru the dash just a nice movement with the throttle until the boat levels on plane. Now the critical part: You can read the boats performance in the feel of the ride and the wake behind the boat. If you have trim tabs and the boat wants to lean over to one side it is likely one tab is not moving. Get this fixed do not compensate with the other tab. If your boat is level its time to find " the sweet spot" this is the trim position that allows the hull to run as free as possible. You find this by tapping and I stress tapping up on the trim button. If you hold the trim button you will run right thru the sweet spot the bow will rise and the boat will start to bob with the bow moving up and down (porpoise, this is bad) if this starts pull the throttles back immediately and start over. If the bow bounces up and down loosely at high speed you can create a stuff. This is when the bow goes up and then on the way down the bow nose dives under the water. We don't want that!

 

As you tap up on the trim button you will feel the speed increase and the motor will change sound as the boat breaks free. What you are trying to achieve is the flattest waves and rooster tail possible with the bow not bouncing up and down. This will take a couple of tries but once you achieve the sweet spot you can pull back on the throttle and experiment with the minimum amount of RPM you need to stay on plane. The hull is free and the motor does not have to work as hard to maintain plane.

 

Things that can effect the maximum performance of your hull and motor. They are:

The engine lacks power from needing a tune up

 

The cavitation or skeg on the drive are broken, this can include dol fins broken

 

Wrong Prop

 

Over loading the boat

 

Having to large a load aft of the center line of the boat.

 

Prop damage

 

 

 

 

 

TRIM TABS

 

Trim tabs should not have to be used in achieving plane. If you are then there is a problem. If the drive is all the way down on some boats which are on the edge of being underpowered than yes tabs will help. If you need the tabs to get on plane or stay on plane then you need to have the boat checked out. Not just mechanically you may have to have it weighed. Tabs are to compensate for uneven loads across the beam of the boat if you have a boat that needs the tabs all the time that's a sign from the boat gods. If nothing is wrong consider selling the boat it is a gross under performer. Trim Tabs are fuel eaters, You can use tab down to punch the bow thru waves but you really need to consider the fuel burn and load on the motors to try and achieve a better ride on a day that the ride is probably going to be bumpy no matter what you do. Slowing down is a better response to big water.

 

If you run with the tabs down all the way and the drive down all the way you can burn twice the fuel that you should. Achieve only two thirds (if your lucky) of the boats performance. As much as you can try to run the boat without any tabs (BOW UP ). If you have to reload the boat it will pay you back. Make the adjustments on the boat rather than with the tabs.

If you are sure to keep the tabs up all the time and only use them when absolutely necessary you will not bend or destroy them when backing down hard. The trim tabs try to act like water breaks when backing up.

 

Besides the boat running leaned over, the other way to know if the tabs are not retracting all the way is when in reverse the boat will pull unnaturally to the left or right. So be sure the tabs operate correctly every time you go out.

 

 

Once you achieve the sweet spot the boat will get the best fuel burn, ride and handling from your boat. All this from the Trim Button and the Trim Tabs. Its not fancy but it works and a lot of boaters have never heard of this information.

 

If you have a boat that won't preform and no technician around video your boat on your phone with sound and E mail it to me I will help you assess the issue .

AUTHOR RP

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