Trailering with Tilt Lever

[Jason2tpa]

Today while driving I noticed a trailered flats boat whose engine was slightly tilted up for road clearance. When I trailer my boat I fully tilt up the engine and engage the tilt lever. Then lower the engine so the lever firmly rests on the bracket (My engine also needs to be tilted up for road clearance, no jack plate).

This had me thinking, what does the manual suggest. See attached file.

I have always seen people trailering boats with their engines slightly tilted up, but never understood why. Driving over potholes or any other hazardous roadway causes the T/T hydraulics to absorb the downward force. I don't see how this can be no big deal.

My transit from boat storage to boat ramp is only 1.5 miles, but even if it was longer I would use the lever down to prevent hydros from absorbing this force. However, as you can read in the manual, this is not recommended.

Can someone explain to me why?

[99yam40]

seems the manual tells you why not to

I have seem many people that do it anyway.
if it bends or breaks something while doing what the manual tell you not to do, then Yamaha is coverd

[boscoe99]

The metal in the bracket can become bent if it is used to support the motor when the boat is being trailered. Can, not will.

Do a test. With the motor tilted full up grab the skeg and lift the motor up and down. In most there will be a good bit of play.

Now grab the skeg when the motor is resting on the trim pistons and try and lift the motor up and down. It will seem as if it is solidly locked into place.

I always towed my boat and motor with the motor trimmed up just enough to provide adequate road clearance. In my case the motor was always resting on the trim pistons.

[Jason2tpa]

So trailering with the engine resting on trim pistons will not effect the hydro T/T system? Man that seems counterintuitive, you know. If your motor weighs 400lbs, you run over a pothole, that's 400lbs of force directed down through hydros. I would just think this can't be good over time.

I can understand why Yam doesn't recommend using the lever in transit, in case it snaps. But ah ha, if it snaps it's because of the downward force it absorbed.

[Jason2tpa]

But maybe I need a lesson on the physics of the hydro T/T system. In my mind, while the boat/motor are operating on the water, the hydros never experience the abrupt downward force of the engines entire weight. Such an abrupt force I would think causes stress on the seals.

But like i said, maybe i need a lesson. Boscoe, you wanna instruct with your super duper schematics?

[pstephens46]

I have seen many of those service props bent outward. Many to the point where I wouldn't feel safe under them with T/T removed. I lift my engine up to where the props will fold down but are not supporting the weight. I am not worried about those hydraulics. And they take a good beating, esp offshore.

[99yam40]

just because a motor weighs 400lbs does not mean the whole weight of the motor is hitting the rams or the lever.
The motor is bolted onto the transom, so the bracket and transom is taking most of the weight.
When driving slow speeds it does not put much on the T&T, but highway speeds and things you can hit can make the motor move very violently.
What those pressures are? Who knows.
can these forces bend or break something? who knows.
But Yamaha has covered themselves just in case some AH tries to sue them

[99yam40]

I have seen many of those service props bent outward. Many to the point where I wouldn't feel safe under them with T/T removed. I lift my engine up to where the props will fold down but are not supporting the weight. I am not worried about those hydraulics. And they take a good beating, esp offshore.

may want to change your post about props, as they have nothing to do with this support lever

[pstephens46]

may want to change your post about props, as they have nothing to do with this support lever

Just insert "weak ass little metal arms" wherever "props" is used.

[TownsendsFJR1300]

The simple "fix" is to tilt the engine at the angle you wish to tow.

Measure between the trim and the when the trim rods would touch.

Now, simply cut some schedule 40 PVC to that length.

Trim the engine up, slip in the two pieces (over the trim rams and lower the engine to hold the PVC.

The engine is NOW supported by the PVC. Nothing to bend, no extra stress (cept to the PVC)

[99yam40]

Just insert "weak ass little metal arms" wherever "props" is used.

If you are going to wait for me to do that ,you will be waiting a very long time as I cannot edit your posts

[pstephens46]

If you want to fully protect your hydros - tilt motor all the way up and extend the service arms. Lower motor down onto said arms. Now get a screwdriver and loosen the manual release on side of bracket. Now the hydros are fully isolated and protected. Not sure about the rest of it. Now drive around.....

What amazes me is how these transoms don't snap off....3 - 350s weigh around 2400lbs bouncing down the road or blasting away over 6 foot swells....

[boscoe99]

But maybe I need a lesson on the physics of the hydro T/T system. In my mind, while the boat/motor are operating on the water, the hydros never experience the abrupt downward force of the engines entire weight. Such an abrupt force I would think causes stress on the seals.

But like i said, maybe i need a lesson. Boscoe, you wanna instruct with your super duper schematics?

Don't have any super duper schematics about this.

Hydraulics can be plenty tough. Fluid is all but incompressible. When the fluid is locked within the trim and tilt cylinders the assembly acts mostly as a solid piece of steel. When the motor is lowered onto the trim piston ends you have the pistons pushing in one direction and the tilt piston pulling the motor down in the opposite direction. Clamping the motor in place. Do this and then see how much the motor can be moved up or downward.

Ever heard of the Southern King Fish Association? They run their twin/triple/quad powered F300/F350's at wide open throttle for hours at a time. Launching off of waves and slamming back down into the ocean. Motor is creating maximum thrust one second and then when the boat departs the water no thrust at all. The motor is weightless for a second or so and then then boat and motor slam back down into the water. Zero thrust from the propeller one nanosecond and then maximum thrust the next second. Acting on the trim pistons. What might all the forces be that the boat and motor see when this happens time and time again? Don't know.

The trim system holds up pretty well all things considered. The wimpy tilt lock bracket, when the motor is tilted fully up, designed only to hold the motor up in place when the motor is being serviced, not so much. It can bend.

[Jason2tpa]

Alriighty then, ill take yalls word of how strong the T/T hydros are. Appreciate all the input and jimmy-rig suggestions.

[TownsendsFJR1300]

Just to add, obviously the trim cylinders will raise the engine only so far. That may be enough for you.

If not, use the PVC trimmed for what you need..

Same thing but save $40.00:

http://www.ebay.com/bhp/outboard-motor-support