JD VIP Buyers Club
JD on Facebook
JamestownTV
Request A Free Catalog

How Do I Use Bennett Marine Trim Tabs?





How Do I Use My Trim Tabs?



Trim Tab Motions Making Small Adjustments
The key to getting the best results from your trim tabs is to operate them in short half-second "bursts" and let the boat react before making another adjustment. The amount of time between corrections is influenced by the size of the trim tabs and the boat's speed.

Avoiding Over-trimming
Operating your tabs this way will help avoid over-trimming, which occurs when you've deflected the tabs too far. An over-trimmed boat will "plow" or "bow-steer." If you over-trim the boat, simply press "Bow Up" and the bow of the boat will rise.

Your boat may have been built to avoid this situation. Bennett's hydraulically-adjustable trim tabs enable a boat to be designed and rigged so it never runs in an over-trimmed condition even at the top end of its speed range. This avoids the hazardous combination of high speed and unpredictable handling.

Finding Your Boat's Optimum Attitude
Operating your tabs this way will help avoid over-trimming, which occurs when you've deflected the tabs too far. An over-trimmed boat will "plow" or "bow-steer." If you over-trim the boat, simply press "Bow Up" and the bow of the boat will rise.

Your boat may have been built to avoid this situation. Bennett's hydraulically-adjustable trim tabs enable a boat to be designed and rigged so it never runs in an over-trimmed condition even at the top end of its speed range. This avoids the hazardous combination of high speed and unpredictable handling.

Wake Trimming From a Bridge or Tower
When steering from a bridge or tower, a good trimming method is to watch the bow spray, stern wake, or the rooster tail. An untrimmed boat will produce more spray aft of the bow and it will produce a larger wake. When trimmed, the bow spray is farther forward, the wake is reduced, and the rooster tail is smaller and farther behind the boat. You'll also notice that the engine RPM will increase when the boat is properly trimmed.

Correcting a Listing Condition Correcting a Listing Condition
As a result of uneven weight distribution, prop torque or wind, a boat can run with a list. Deep "V" hulls are particularly vulnerable to this condition. Running with a list is uncomfortable, as well as unsafe. Bennett Trim Tabs operate independently for effective list correction.

You can easily bring the boat level using your control. If the port bow is high, push the port side "Bow Down" direction (this lowers the trim tab on starboard side). If the starboard bow is high, push the starboard side "Bow Down" direction until the boat is level (this lowers the trim tab on the port side).

During Take-Off
Properly sized trim tabs can significantly reduce the time needed to get up on plane. They also allow a boat to keep its bow down and stay on plane at lower speeds.

As the throttle is advanced, the stern of the boat begins to squat, lifting the bow. As the boat accelerates, push the bow down position of the helm control in short bursts. The boat reacts by the stern lifting, the bow coming down, speed increasing and the engine laboring less.

Prop Using Your Power Trim and Trim Tabs Together
It is a common misconception that if a boat has power trim on the outboard or outdrive it does not need trim tabs. Yes, power trim can be used to adjust the boat's attitude, but it is highly inefficient.

This is because a propeller is designed to force the boat forward. When trimming the boat with the prop, the prop must not only push the boat forward but raise the stern as well. In this situation, prop slippage is greatly increased thereby wasting RPMs. Power trim also cannot correct listing, and is ineffective at slower speeds.

For increased speed and power, use your trim tabs WITH your power trim. Bennett Trim Tabs, in combination with power trim, enable both the hull and prop to be trimmed independently. The trim tabs trim the hull, while the power trim adjusts the prop. The result is optimum performance and efficiency not attainable by the use of power trim alone.

To achieve maximum performance:
1. Adjust the trim tabs to achieve a planing attitude.
2. Use the power trim to position the prop path parallel to the water flow.
3. If necessary, re-adjust the trim tabs to "fine tune" your tabs. In other words, use your trim tabs to trim the boat and your power trim to trim your prop.

Changing a Boat's Attitude to Match Sea Conditions

Choppy Head Sea
For the most comfortable ride, when running into a head sea you want to trim the bow down so the sharp forward sections of the boat do their work cleaving the waves. This will bring the "V" of the hull in contact with the waves rather than having the waves pound the hull - and your passengers.

Following Sea
For best maneuverability and maximum steering control, trim tabs should be fully retracted in a following sea, or when running an inlet. Keep the tabs up so the tide or current won't push the stern from side to side.

Beam Sea
Boats operating with waves approaching from the side often throw spray up on the windward side. This spray often is carried aboard by the wind (particularly on smaller vessels). Trim tabs are used to raise the windward side of the boat, blocking the spray that blows over the boat, resulting in a drier ride.

Correcting Porpoising
Porpoising is a condition more common in faster, performance boats. As speed increases, the bow repeatedly rises out of the water until gravity overcomes lift and the bow bounces down. Press "Bow Down" in half second bursts. As the trim tabs deflect, the porpoising subsides and your speed should remain the same or increase. Only a slight amount of trim tab deflection should be necessary.

Backing Down
When operating the boat in reverse, both trim tabs should be fully raised. The trim tabs produce drag if they are left down in reverse. This puts strain on the tabs as well as affects the boat's handling in reverse. Additionally, if one tab is deflected more than the other in reverse the boat tends to pivot around the deflected tab. Properly installed tabs, fully retracted have no effect on backing down.



JD on Facebook Live Tech Support JD Customer Photo Gallery Free Catalog