How Trim Tabs Work Bennett Trim Tabs are attached to the bottom edge of the transom. When the helm control is pressed, the trim tabs move into position. Water-force on the trim tab surface creates upward pressure, raising the stern and lowering the bow. Properly sized Trim Tabs improve the performance of your boat in a much wider range of weight, weather and water conditions. Bennett Trim Tabs operate the reverse of what you might think. The port trim tab lowers the starboard bow. Conversely, the starboard trim tab lowers the port bow. The control is wired so that all you have to do is press the control in the direction you want the bow to move. Dont worry about which trim tab is moving. The proper use of Bennett Trim Tabs becomes second nature after a short time. How To Use Your Trim Tabs Getting and staying trimmed Most boats break over (get on plane) at a particular speed. This speed is determined by weight distribution, water conditions, etc. Bennett Trim Tabs enable your boat to plane at speeds lower than natural planing speed. By pressing the control to the Bow Down position, your trim tabs move down. This will raise your stern and lower your bow, getting you up on plane faster and increasing your speed. Your Boats Optimum Attitude A good way to find your boats optimum attitude is to conduct this test. Get out and run it lightly loaded, at full speed on flat water. Notice the bow in relation to the horizon. This should be your boats best running attitude. You can use your trim tabs to recreate this perfect attitude regardless of weight distribution, speed or water conditions. Getting Used to the Feel of Your Tabs When learning to use your tabs, begin by pressing the helm control in half second bursts for gradual trimming. A momentary delay occurs from the time you press the control to the time the boat reacts. This is normal, and varies with boat speed. Be careful not to over-trim your boat. 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. 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 will also notice that the engine RPM will increase when the boat is properly trimmed. Running In Rough Water When running in a chop or heavier seas, press Bow Down. This will bring the V of the hull in contact with the waves rather than having the waves pound the hull and your passengers. In a following sea or when running an inlet, the trim tabs should be fully retracted for maximum rudder response. Correcting for a List Bennett Trim Tabs are operated individually so that you can correct for listing. your control is designed so that you can use it intuitively. Do not think about what the trim tabs are doing, just concentrate on the bow. If the port bow is high, push the port-side Bow Down direction. If the starboard bow is high, push the starboard side Bow Down direction until the boat is level. Trim Tabs with Power Trim Using your trim tabs in conjunction with your power trim will give you increased speed and power. Adjust the trim tabs to achieve a planing attitude. Use the power trim to position the prop path parallel to the water flow. 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. Correcting For 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. Safety Precautions -Do not overtrim, particularly at high speeds as the bow will dig in and wave action may cause the boat to veer. -While underway, do not move one trim tab significantly farther down than the other as undesirable listing could occur. -Use your trim tab helm control with caution. -For best maneuverability, trim tabs should be fully retracted in a following sea, or when running an inlet. -Improper use of trim tabs can cause an accident or injury. Bennett Trim Tabs have a significant effect on the operation and versatility of your boat. no one knows your boat better than you, the best learning method is to spend time getting familiar with your boats reaction to the trim tabs. As your experience with Bennett Trim Tabs increases, so will your enjoyment. Always operate your boat with safety first in mind. System Information Maintenance - Periodically, check fluid level in HPU. With trim tabs completely retracted, fluid level should be about 2 inches from bottom of reservoir (approximately 22 ounces). To refill, remove lexan cover and filler plug located at the front left hand corner of the reservoir. FILL WITH ANY TYPE AUTOMATIC TRANSMISSION FLUID (ATF) ONLY . Brands or types of ATF can be mixed. Running HPU with an excess or lack of fluid will not cause damage. - Periodically, check for clean electrical connections on back of control, HPU ground wire, and quick-disconnect plug. - Cold temperatures do not affect the trim tab system. No winterization is necessary. - (SALTWATER ONLY ) To deter electrolysis, a zinc anode should be attached to the top of each trim tab. Zinc must make direct contact with stainless steel. Do not paint zinc. Do not ground trim tabs to other underwater appendages. - Paint trim tabs to discourage marine growth. Clean surface of all grease, oil, dirt. Apply two coats of epoxy metal primer. Apply two coats of anti-fouling paint. Actuator, including the piston, may be painted. - Unpainted trim tabs may acquire an orange discoloration. THIS OXIDATION OF SURFACE CARBON MOLECULES IS NORMAL. The integrity of the stainless steel is not affected. Orange coating can be cleaned off, but may eventually return. Note: This discoloration should not be confused with the pitting and corrosion of electrolysis. Safety Information - Take immediate action to correct any malfunction or failure of your trim tabs. - Occasionally, check for loose or corroded wiring connections. - Stepping on the trim tab may cause damage to the unit, or injury. - Make sure the HPU is mounted in a dry location to avoid drenching and consequent failure. - Leaving the actuator extended when boat is not in use will not cause seal damage. - Occasionally, inspect HPU fluid level. The information provided here has been reproduced courtesy of Bennett Trim Tabs. Wholesale Marine reproduced this information 07/15/2009. #Product Information #Trim Tabs
