Trailering motor position - Transom Saver Bar?

[ezaction]

The manual for my Suzuki DF70 says to "keep the motor in the normal operating position" while trailering "unless there is not enough ground clearance." I don't think there is enough clearance.

In that case the manual continues "trailer the motor in a tilted position using a transom saver bar or similar device to support the weight of the motor":!:

Does anyone actually use a transom saver bar? Do you leave the motor up or down while trailering:?:

[Chip Hindes]

We've had this discussion at length on the old board.

Assuming you could get one that would work (since the motor is well aft of the end of the trailer, I believe a "transom saver" bar that hooks to something on the trailer (as most do) is a very bad idea on the Mac. Reason being the Mac trailer is designed to flex quite a lot during normal over the road trailering. The trailer flexing will in turn transfer extreme loads through the transom saver bar directly to the motor and transom, and those loads will be much higher and much more detrimental to both the motor and transom than without.

The question remains, what to do about the fact that at least in theory, neither the power tilt cylinder nor the "tilt stopper" mechanicsm (Tohatsu terminology) are designed to carry the weight of the tilted motor. I have a block that wedges in between the bracket which carries most of the load.

[Dimitri-2000X-Tampa]

Is it an issue of carrying the weight of a tilted motor..or.. the moment of force on the transom being more extreme when the motor is tilted versus when it is down?

[Chip Hindes]

Good question.

Of course the weight of the motor is the same whether the motor is tilted or straight.

In fact, the motor tilted up is quite well balanced, so the static moment of the tilted up motor is pretty close to zero. The tilted down motor has some considerably higher static moment. On the trailer going down the road the motor bounces up and down and creates additional forces; these are not easily calculated and would pretty much have to be measured, but in any case they will still be higher with the tilted down motor than the tilted up motor.

I question why a motor manufacturer would recommend the boat be trailered with the motor down; it may in some way be easier on the motor although I don't see how; it certainly is quite a lot harder on the boat.

Here's some more things to think about. While in the water with the motor driving the boat, it generates a substantial moment. It would be relativley easy to calculate based on motor torque, but whether greater or less than the trailering loads, I couldn't say.

Think of the loads generated when you hit an underwater obstacle with the lower unit hard enough to kick the motor up. I've heard of people doing this, but I've never heard of anyone damaging the transom by doing so.

[Frank C]

OTHER - and by way of "splanation" ...

As does Chip, I block the motor in tilt-up position with a short length of 1x2, cut to exactly fit in a couple of motor/saddle crevices. It has always seemed to me that there's better balance this way, and I could not better Chip's explanation of this. The motor dealer told me that Suzuki advises NOT to rely on the tiny flip lever, since they fear that road-jounce could apply too much loading on the tiny bearing surface of that lever, possibly cracking a casting.

The hydraulic cylinder is fully presurized in both directions, but road-jounce could be rough on the seals. Even so, I tow the few hundred yards from storage to ramp with no extra support. Dealer never mentioned that the motor be carried in vertical, probably because it's obvious that would be lunacy.

[Chip Hindes]

I would imagine towing with only the tilt cylinder holding the motor is hard on the seals, but note that our blocks are only protecting against forces in the downward direction; resistance to forces in the upward direction is still provided only by the tilt cylinder.

The big problem with depending on the tilt cylinder is the hydraulic system is designed with a pressure relief built in; that's what permits you to hit the up or down mechanical stops without blowing them, and also to hit stuff while underway and the motor kicks up (hopefully) without damage. Put a large enough load on it, and the relief will relieve, just like it's supposed to. If the motor tilts up, no problem; If it drops you can guess the rest.

[Dimitri-2000X-Tampa]

As we can see from the poll, most people seem to be disreguarding the motor manufacturer's recomendation out of pure common sense. I have to admit, the ground clearance of the lower unit on the Mac is not too bad considering how low the boat rides on the trailer...so I do get tempted to trailer with motor down sometimes. But since I've heard stories of other people striking the motor skeg when pulling the boat off of a ramp, I try to always tilt mine at least halfway up. I suppose that has something to do with the slope of the ramp too.

I guess the jury is still out on this one as common sense seems to contradict the motor manuals.

One other interesting note, I also keep my motor tilted up while trailering just in case some bozo runs into the back of me. I figure a strike to my motor will at least nicely gouge their radiator and make them stop before hitting my transom and rudders....or at the very least, keep them from following too closely And of course, if someone did hit me, then that will then make for a better reason to upgrade my motor than I currently have.

[Dimitri-2000X-Tampa]

Oh yea, and another thing...I expect the kind of tow vehicle has a lot to do with it too. My minivan (and probably everyone who is not towing with a good sized truck/SUV) hitch sits quite a bit lower than someone towing with an F-350 or something. This must be increasing my ground clearance on the motor quite a bit. See....there is at least ONE good reason not to tow with a monster truck!

[Tom Root]

I recall the easy fix that was reccomended on the old board was to run a rope or a tie down, from one rudder cleat, around a lower point on the motor, ( I use the area below the cavitation plate) one wrap around and back up to the other cleat!

Simple fix, and this transfers loads better, and lessens the pressure on the motor and transom. I only rig this when not running down the freeway, and going to be on alot of surface streets or unimproved roads, but should make it a habit to do this all the time! I also have the motor tilted up, as down seems like sooner than later, one would end up replacing a perfectly good motor.

Tom Root
2002 26
Great White
San Diego

[Sloop John B]

The manufacturer wants you vertical so you don't load up your cylinders with oil.

Doesn't work in the Mac.

Only thing to do is raise up to clear the road and put a piece of pine between the engine and bracket and let it 'rest' on that.

[RHC]

[Only thing to do is raise up to clear the road and put a piece of pine between the engine and bracket and let it 'rest' on that.]
Can someone pls post a picture/sketch exactly where this pc of wood is wedged??[/quote]

[Moe]

This is what I use

--
Moe

[jsserene]

I have been using Moe's mod for a while now. It is easy to make, install, remove and it works great.

[Mark Prouty]

I voted other. Let me 'splain.

This was a major concern of mine when I first bought my motor. I also block the motor in tilt-up position. I use a short length of 2x2.

I would like to have a transom saver bar but there is no logistical way to install one on a Mac trailer. (3 votes for "Up, with transom saver bar" prove me wrong )

[kmclemore]

OK, so I use the 'kick-stand' that came on the Tohatsu... I raise the motor up, drop the lever which lowers the stand, then lower the motor onto that holder (stand). Seems to work OK.. am I crazy?