Transom Savers and Motor Supports: How to Trailer Your Outboard or Sterndrive

Start with the "trailering" or "storage and transportation" section of your engine's owner's manual, then the boat builder's manual or dealer. Some boat packages ship with a support; others say not to use one. Write down the trailering position your engine maker wants (full down, tilted, or the "trailering" setting on some sterndrives) and whether they specify a support.

Mercury's advice is that towing with the outboard vertical puts the least strain on the motor and the transom, and its tow-prep checklist says the same keeps wear off the hydraulic tilt system and engine mounts. The catch is ground clearance.

• With the boat on the trailer and the trailer hitched (so the tongue is at towing height), lower the motor fully.
• Measure from the bottom of the skeg to the ground.
• Then think about the worst spot you drive over: the dip where your driveway meets the street, a steep ramp, a speed bump.

If the skeg clears all of those with room to spare, Mercury says riding vertical is the way to go. If not, you'll tow tilted, and then a support is recommended.

This is the one point every maker agrees on.

• Yamaha's FAQ: the tilt support lever is for storage only, wasn't designed for the strain of transport, and could break and damage the bracket. Yamaha points owners to its trailering support accessory.
• Suzuki's FAQ: same warning, and it suggests an aftermarket transom saver designed to work with your specific Suzuki.
• BoatUS adds that power tilt was never meant to hold a motor over potholes and dirt roads, only to lift it in shallow water or at the ramp.

Other brands have similar levers and similar warnings. If yours is flipped down when you hitch up, that's fine for parking in the driveway, not for driving.

Use the BoatUS findings as a checklist. A support makes the most sense when:

• The boat is small or light and the motor is heavy for it (jon boats, bass boats, aluminum boats, setback brackets or jack plates)
• You have to tow tilted because of low clearance
• You tow long distances or on rough or unpaved roads

The argument against: a trailer-mounted bar moves load from the transom (built to carry the motor) to the trailer, and because the boat and trailer bounce separately, road shock can come back up the bar into the lower unit. Some critics also point out that motor-mounted wedges protect the tilt rams but take nothing off the transom. If your builder says no support, follow the builder, and keep checking the transom (step 12).

• Trailer-mounted bar: works with or without power trim. Best when the motor tends to move up and down on the tilt pivot, for example a manual-tilt motor. Needs a sturdy spot on the trailer (rear cross member or roller bracket) and a yoke that fits your gearcase.
• Trim-ram support (wedge or tube): small and easy to store. You trim up, slip it over the ram, and trim down until it's snug. Only for motors with hydraulic trim, and only one designed for your model. Yamaha notes its own support doesn't fit every model.
• Lower-unit-to-bracket rods: also need power trim; they hold the motor in relation to its own bracket rather than the trailer.
• Sterndrives: Mercury's tow checklist mentions a trailer support bracket or clips to hold the sterndrive unit high enough to clear the road. Use only the type and position your drive's manual allows. Owners of older sterndrives often find the drive slowly settles toward the pavement on the way home from buying the boat. Don't wedge a board in and hope: stop, raise the drive to its trailering position, and fit the support or bracket made for that drive before you continue. A drive that won't stay up also points to a trim system that needs checking.

Bar or motor tote? Boating Magazine put the question to a maker of motor totes (the brace that sits between the trim rams and the tilt bracket), and even he said neither is better everywhere:

• A trailer bar is often the better pick on small aluminum boats or older fiberglass boats with wood-cored transoms, because it lets the trailer carry part of the motor's weight instead of the transom.
• A tote makes motor and boat move as one, so there's no gap to change as the boat bounces on the trailer, and nothing rubs the gearcase finish (the V-cradle of a bar often scratches it). A tote does need steering locks or clips to stop the motor flopping to one side, and its tilt height is fixed.
• On twin or triple outboards, or a motor on a long setback bracket, a trailer bar is often impractical, and totes are usually the answer.

Mercury suggests asking a marine professional which size and type suits your boat, trailer and engine. A dealer can tell you if your engine has a built-in trailering support (BoatUS noted that some Evinrudes came with a spring-loaded lock arm) or a factory accessory.

For a trailer-mounted bar:

1. Tilt the motor to the height you want for towing, enough to clear your worst dip but not higher than necessary.
2. Measure from the point where the yoke will sit on the lower unit to the trailer mounting point.
3. Pick a bar whose adjustment range covers that length with room to spare. Adjustable bars let you fine-tune.
4. Check that the yoke fits the gearcase without touching the propeller, the speedometer pickup or other small parts. If the instructions show where on the lower unit it should rest, use that spot.

For a trim-ram support, buy the size listed for your engine model, not "close enough."

• With power trim: BoatUS explains that the motor should be trimmed down onto the support until hydraulic pressure holds it in place. Snug is the goal. Don't keep running the trim down after the support is loaded: that pushes hard on the bar, the gearcase and the transom.
• Without power trim: the bar must be strapped or bungeed at both ends so it can't pop out as the motor bounces.
• Wiggle the motor by hand at the lower unit. It should feel solid, with no clunk.
• Center the motor or drive before you snug it down. A Mercury engineer quoted by Boating Magazine says to trim down "reasonably tight" into the saver's cradle, without overdoing it. If you tow with no support at all, tilt up just enough to clear the road, and don't rest the motor on the flip-down tilt lock, which he says is meant to take load off the tilt system while the boat sits in the water, not road shocks.
• Look at the bar from the side: it should be straight, both ends fully seated, with no sharp edge digging into paint.

BoatUS reports a classic complaint: a support that works fine on the highway, but the skeg still scrapes as the trailer drops from a raised driveway to the street, or the other way on the way home. Have a helper watch from the side while you drive slowly over your driveway transition, then over a speed bump. If the skeg comes close, raise the motor a little and readjust the support, or take that spot at an angle.

• Steering: keep the motor pointed straight back so the yoke stays centered. If it swings side to side on bumps, the bar can roll off the gearcase.
• Propeller: a BoatUS trailering tip is to put the engine in gear so the prop doesn't spin in the wind.
• Covers: only use an engine cover made for towing (see our pre-trailering checklist).

Stop and fix it if you see any of these:

• The bar rattles, rotates or has slid along the gearcase
• One end is half off the roller or bracket
• Fresh scrape marks on the gearcase, skeg or prop
• The motor sits lower than when you left (the trim may be bleeding down, or the support is collapsing)
• A spring-type bar is fully compressed at rest

Risks of getting it wrong include the bar popping out and the motor dropping, a gearcase or skeg cracked by a point load, a bent trim ram, and a support that hammers the lower unit instead of cushioning it.

At the ramp, raise the motor slightly, remove the support and stow it in the tow vehicle before you back in. Trimming down against a forgotten support can damage the support, the trim system or the transom. Add it to your launch routine next to the drain plug and transom straps, and put it back only after the boat is on the trailer and out of the ramp lane.

• Every trip: look over the support after the first few miles and at every fuel or rest stop, along with the straps and hubs.
• Each season: inspect the yoke pads, pins and springs, and replace worn pads so bare metal never rests on the gearcase.
• Each season: look for cracks around the motor mounting bolts and the transom corners, and on aluminum boats for cracked welds or loose rivets. Our transom and stringer rot guide covers what to look for. Damage there is a reason to call a pro, with or without a saver.