Engine support while towing.

[KJM]

Just wondering how people support a heavy OB on the transom while towing. My tow to the water is only short, 5 min., but I still cringe when I go over bumps and think of the motor bouncing on the transom. I have an F90 Yamaha. I just keep it at full up with the small lever down to take the strain of the tilt motor. Is this OK or should I get some kind of Transom saver? Would it be better to transport with motor half down?

 

[topgun3690]

If you have to tow with engine tilted up, for clearance, then use a transom saver....without it, the engine will cause the transom to flex fore and aft.....and the higher the motor is the worse the flexing will be.

 

[jimmbo]

If the Motor can be locked Hydraulically in the Up Position, I wouldn't use a Transom Breaker, as any shift of the boat on the trailer places a huge Stress on the Transom. If the Motor is tilted up and can bounce around, then I would use one

 

[JimS123]

They make a rubber outboard support bracket that fits over the trim cylinder. I have one for both my large Mercs. They make them for Yami as well. Google it.

 

[Scott Danforth]

Motor deflopinizer

 

[jlh3rd]

Just wondering how people support a heavy OB on the transom while towing. My tow to the water is only short, 5 min., but I still cringe when I go over bumps and think of the motor bouncing on the transom. I have an F90 Yamaha. I just keep it at full up with the small lever down to take the strain of the tilt motor. Is this OK or should I get some kind of Transom saver? Would it be better to transport with motor half down?

I've got a '21 merc 115 hp, CT motor. I'm sure your 90 weighs close to mine.
Previously had a merc 60 on my pontoon and didn't use a transom saver, never really noticed it bouncing much. But this 115 bounced like crazy, so I use a transom saver. I also learned not to use the tilt lock for trailering, per the manual.
FWIW ...I tried one of those trim actuators block devices. I did not like seeing the motor and transom still moving and flexing.

 

[KJM]

I've got a '21 merc 115 hp, CT motor. I'm sure your 90 weighs close to mine.
Previously had a merc 60 on my pontoon and didn't use a transom saver, never really noticed it bouncing much. But this 115 bounced like crazy, so I use a transom saver. I also learned not to use the tilt lock for trailering, per the manual.
FWIW ...I tried one of those trim actuators block devices. I did not like seeing the motor and transom still moving and flexing.

I noticed that the tilt lock is not recommended but I don't understand why? You would think that would be better then letting the trim hydrolics take the strain.

 

[dingbat]

I noticed that the tilt lock is not recommended but I don't understand why? You would think that would be better then letting the trim hydrolics take the strain.

A hydraulic cylinder by design is a shock absorber... your tilt lock not so much

 

[Scott Danforth]

I noticed that the tilt lock is not recommended but I don't understand why?

Because it will break

 

[KJM]

I think I will go with a My-Wedge type design. I guess I'll stop using the tilt lock!

 

[airshot]

While you boat is underway at speed, the power trim is under far more strain than when it is just holding your motor while traveling down the road. If you have power TT, use it...thats what it is there for.

 

[guy48065]

While you boat is underway at speed, the power trim is under far more strain than when it is just holding your motor while traveling down the road. If you have power TT, use it...thats what it is there for.

You're describing static loads. The TT cylinder might behave like a shock absorber but it may not be designed to take the dynamic shocks of bouncing over potholes & RR crossings. The cast aluminum brackets probably aren't designed for those extremes either.

 

[jlh3rd]

it's the transom that's taking the brunt of bouncing and flexing when trailering. That's why they're called transom savers.
If the motor could be balanced evenly over the center of the transom and kept there, and the transom was exactly vertical, you probably wouldn't need anything, except for braking and accelerating forces. However those forces are normally smooth and gradual.
My pontoon's transom is slanted therefore the load isn't carried 100% vertically. And the bouncing motor puts additional fore/aft twisting, jerking movement on the transom and motor mount.
To me, it's not the same as the "smooth", in line push from the motor in the water.

 

[ScottinAZ]

when I had an outboard, I used a transom saver. I just didnt like the idea of the heavy motor being able to move around even a little bit, and transferring those loads (even an old Evinrude 115 isnt light) to the transom. Now that I have an IO, I just put a block on the trim rams to keep the drive in the "up" position. The difference is that with an Outboard, you have several hundred pounds hanging on the upper edge of the transom, whereas on an IO, its a hundred pounds or so coming through the transom with the heavy engine inside supported by the rest of the structure of the boat. Anything to reduce the large bouncing loads, and the extreme stresses that puts on 2" of plywood and fiberglass, especially as the boat gets older.

 

[jlh3rd]

aluminum pontoon transoms don't like excessive flexing either

 

[ScottinAZ]

aluminum pontoon transoms don't like excessive flexing either

I wouldnt think so. An outboard is a LOT of weight that can produce a lot of movement on perhaps the most critical part of the boats support. Transom savers are named such for a reason. Are they perfect.... no. Can they potentially cause more harm than good..... Maybe..... are they better than nothing.... I would say YES..... IMHO, anything to limit the bending at one of the most unsupported parts of the transom is a good thing.

 

[airshot]

You're describing static loads. The TT cylinder might behave like a shock absorber but it may not be designed to take the dynamic shocks of bouncing over potholes & RR crossings. The cast aluminum brackets probably aren't designed for those extremes either.

According to Mercury on both my previous I/O and my current 92 classic , the factory claims the TT is more than adequate for trailering if the motor/ outdrive does not have to be raised all the way up to a trailering position for clearance. I have gone to great lengths/ extremes to get both the outdrive and my outboard to move while being held in position by the TT cylinder, never had one move, not the slightest !! Even trying to force it...no movement. Even the added braces for the outdrive cylinders that I had, the instructions stated they were only needed if the cylinders are worn or there were issues with the hydraulic system....

 

[ScottinAZ]

According to Mercury on both my previous I/O and my current 92 classic , the factory claims the TT is more than adequate for trailering if the motor/ outdrive does not have to be raised all the way up to a trailering position for clearance. I have gone to great lengths/ extremes to get both the outdrive and my outboard to move while being held in position by the TT cylinder, never had one move, not the slightest !! Even trying to force it...no movement. Even the added braces for the outdrive cylinders that I had, the instructions stated they were only needed if the cylinders are worn or there were issues with the hydraulic system....

in this instance I see the braces as added insurance. My drive will stay up without the braces almost indefinitely, however, the one time they would drop would inevitably be when dragging it down the road.... for what they cost, its cheaper than a ruined trip and a FUBAR drive (I dont have clearance to leave the drive down when on the trailer)..... I also see the transom savers in the same light, as parts will fail at the most inopportune moment...... they may not help, but they sure dont hurt either (in most cases)

 

[jlh3rd]

yeah...they're transom savers, not TT savers, or outdrive savers.

 

[guy48065]

They're all that.