Trim is the running angle of the motor against the transom; tilt is lifting the motor out of the water; the shallow-water position is a partial tilt you can run in, slowly, where the water is thin. On Suzuki portables up to 30 hp the trim angle is set by a tilt pin in the swivel bracket, full tilt is held by a tilt up lock arm, and the shallow-water position is a click detent part-way up. The exceptions: the power-tilt DF9.9B/15A/20A models tilt with a switch but still trim with a bolted pin, and the DF25AT/30AT family trims and tilts with its power trim and tilt (PTT) switch.
The speed rule: in a shallow-water position the manuals say “proceed with caution and only at very low speeds”; power tilt and PTT models put a number on it: “Do not operate the engine above 1500 r/min or operate the boat in a planing attitude with the engine beyond the maximum trim position.”
Which system your motor has
| Family (manual) | Trim adjustment | Reverse / tilt lock | Shallow-water position | Speed rule printed |
|---|---|---|---|---|
| DF2.5 (2019) | Tilt pin with nut, lock nut and spacer | Reverse thrust stopper | Not described in the manual we have | “only operate the motor at slow speeds” |
| DF4A/DF6A (2020–2024) | Tilt pin | Automatic in REVERSE; off in the shallow-water position | Two click positions | “only at very low speeds” |
| DF8A/DF9.9A (2014) | Tilt pin | Tilt lock lever: LOCK (down) / RELEASE (up) | Two click positions | “only at very low speeds” |
| DF9.9B/9.9BR, DF15A/15AR, DF20A/20AR (2019 manual) | Tilt pin | Tilt lock lever: LOCK / RELEASE | Two click positions | “only at very low speeds” |
| DF9.9BT/9.9BTH, DF15ATH, DF20AT/20ATH (power tilt) | Bolted tilt pin | Power tilt; tilt up lock knob for parking | Tilt beyond normal trim with the switch | Not above 1500 r/min beyond maximum trim |
| DF25A/DF25AR (2019 model year) | Tilt pin | Release lever: LOCK / RELEASE | Two click positions | “only at very low speeds” |
| DF25AT/25ATH, DF30AT/30ATH (PTT) | PTT switch | PTT; tilt lock lever for parking | Tilt beyond normal trim with the switch | Not above 1500 r/min beyond maximum trim |
The model code tells you the row: T is power trim and tilt (power tilt on the DF9.9B/15A/20A) with remote control, TH is power trim and tilt with a tiller.
Manual-tilt motors: tilt pin, lock arm and shallow-water detent
Trim (tilt pin). Lock the motor in the fully tilted up position, reposition the tilt pin in the desired holes, lower the motor and make another test run. On the DF2.5 the pin is retained: turn the lock nut counterclockwise while holding the nut, loosen the nut, pull the spacer and tilt pin out to the limit on both sides of the swivel bracket, move the pin, push them back in and tighten both nuts.
Full tilt (tilt up lock arm). Shift into NEUTRAL. Where there is a tilt lock lever (the release lever on the DF25A), move it to RELEASE; on the DF2.5, turn the motor to the front to free the reverse thrust stopper. Built-in tank: turn the fuel cock lever to the right (off) and tighten the air vent screw on the filler cap first, or fuel can leak; DF4A/6A on a separate tank: disconnect the fuel line and fit the fuel connector cap. Grab the handle on the back of the motor cover and tilt all the way up until the tilt up lock arm locks automatically. To lower: lever to LOCK, pull the motor slightly toward you (DF2.5 and DF4A/6A: pull up on the lock arm) and let it down slowly. Lower the motor before opening the air vent screw again.
The tilt lock lever. LOCK (down) is for REVERSE and normal deep-water running where there is no likelihood of striking underwater objects; it stops propeller thrust in reverse, or rapid deceleration, lifting the motor out of the water. RELEASE (up) is for FORWARD gear when you are unsure of depth or concealed objects; the motor can tilt up if you strike something, and you run only at very low speeds. To shift into REVERSE (DF8A/9.9A): lever to LOCK, throttle to idle, push the shift lever away from you firmly. On the DF4A/6A the tilt lock is automatic: shifting into REVERSE locks the motor.
Shallow-water position. Shift into NEUTRAL, lever to RELEASE where there is one, slowly tilt the motor up until you hear a click, then slowly lower it; it stops slightly tilted up from the normal trim angle. There are two positions; use whichever suits the depth. Proceed with caution and only at very low speeds, keep the water intake holes in the water with water spraying from the discharge hole, and back in deep water release the position and put the lever in LOCK (DF4A/6A: pull the motor toward you until it clicks, then let it down). In the shallow-water position, or with the lever in RELEASE, the tilt lock will not work: propeller thrust in REVERSE, rapid deceleration or striking an underwater object can lift the motor out of the water, resulting in personal injury.
DF2.5. The manual we have describes no shallow-water detent. It says to run only at slow speeds in shallow water and not to let the motor hit bottom, particularly in reverse, where the shock acts directly on the transom and can damage both motor and boat.
Power tilt (DF9.9BT family) and power trim and tilt (DF25AT/30AT family)
The switch. Press the upper (right) part to tilt the motor up, the lower (left) part to tilt it down. On the DF9.9BT/9.9BTH, DF15ATH and DF20AT/20ATH that is all it does; running trim is still a tilt pin, now bolted: lock the motor fully up on the tilt up lock knob, loosen the bolts securing the pin, reposition it, tighten the bolts securely, lower and test. On the DF25AT/25ATH and DF30AT/30ATH the switch is the trim adjustment: make a test run, adjust with the PTT system, and if you still cannot get good performance the manual says there may be a problem with engine mounting height; consult your dealer.
Parking lock. Tilt all the way up with the switch, push in the tilt up lock knob (DF9.9BT family) or pull down the tilt lock lever (DF25AT/30AT family), then lower with the switch until it takes the weight; to release, tilt all the way up and pull the knob out or the lever up. It relieves pressure from the power tilt and is for a stationary boat only, never for trailering. The remote switch works with the ignition off, so a hand on the knob or lever can be injured if someone presses it.
Tilting by hand. Turn the manual release screw two turns counterclockwise, move the motor, then retighten the screw. Ensure your grip and footing are secure and that you can support the weight of the engine. The DF9.9B service manual's first check for a motor that creeps downward afterward is to ensure the release valve is fully closed.
Shallow water. Tilt beyond the normal trim angle with the switch, run only at slow speeds, and lower to normal trim when back in deep water. Do not operate the engine above 1500 r/min or in a planing attitude beyond the maximum trim position: the water intake holes may be above the water line, which can result in severe engine damage from overheating, and on the DF25AT/30AT the swivel bracket loses its side support from the clamp bracket, so the tilt system cannot cushion a strike on the lower unit. If the motor hits bottom, inspect it immediately for damage.
Trim tab (all DF25A/30A). If the boat veers, loosen the trim tab bolt, move the rear end of the tab toward the side the boat veers to, tighten and re-check. See DF25A vs DF30A and the DF9.9B, DF15A and DF20A guide.
What changes above 30 hp
On the DF40A/50A/60A, trim adjustment is the PTT system. The 2022–2024 manual keeps the same 1500 r/min limit beyond maximum trim, but the manual release screw is four turns counterclockwise, not two, and it adds a warning the DF9.9B/15A/20A and DF25A/30A manuals we have do not: repeated operation of the PTT overheats the PTT motor and a protection circuit may stop it; the switch is inoperative until the overheating is resolved. The DF50AV/60A/60AV can also have a tilt upper limit set if the motor contacts the motor well at full tilt. Faults are covered in Suzuki power trim and tilt troubleshooting.
Warnings the manuals repeat
- Never place your hands near the mounting bracket or under the motor when tilting it.
- Never use the throttle grip handle to raise or lower the motor.
- Do not operate the motor with the tilt pin removed; you may not be able to control steering.
- The power tilt or PTT switch can be accidentally activated when the ignition key is off, resulting in injury; keep all persons away from the motor.
- Never use the tilt up lock arm, tilt up lock knob or tilt lock lever to hold the motor up when trailering; the DF4A/6A and DF25A/30A manuals say to use a transom saver bar or similar device. See transporting and trailering an outboard.
- Disconnect the fuel line whenever you leave the motor tilted up for a long period of time.
- Tilt the motor out of the water and lock it whenever the boat is powered by an alternative source.
Choosing a trim position
Make a test run to see whether the trim angle needs adjusting. To lower the bow, move the pin toward the boat; to raise it, move the pin away from the boat. If the trim angle is too small, the boat may plow or bow steer; if too large, it may chine walk from side to side or porpoise up and down. After any change, make another test run. Trim cannot fix mounting height: every manual wants the anti-cavitation plate 0–25 mm (0–1.0 in.) below the bottom of the boat with the motor fully lowered; too high and the propeller slips and the motor can overheat, too low and drag costs speed. Setting that is in the portable outboard mounting guide.
Parts for this job
Tilt pins, lock arms, levers, knobs and PT/PTT parts are in Suzuki trim and tilt parts; swivel and clamp brackets are in swivel brackets and mounts; complete motors from the DF2.5 to the DF30A, manual and power tilt, are in Suzuki outboards. Have the model code and serial number ready. Boat Max Online is an authorized Suzuki, Honda and Yamaha dealer; orders over $149 ship free to the lower 48, and motors ship free.
Sources: Suzuki owner's manuals for DF2.5, DF4A/DF6A, DF8A/DF9.9A, DF9.9B/DF15A/DF20A, DF25A/DF30A and DF40A/DF50A/DF60A; the Suzuki DF9.9B/15A/20A service manual (power tilt supplement). Figures are Suzuki's published values; confirm against the manual for your model year and serial number.