Check your outboard jack plates!

H20Rat

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Re: Check your outboard jack plates!

I would call into question the safety of these jack plates. And also the motor that was mounted on there.

My 95 Evinrude 70hp has a hydraulic shock absorption system for just this type of situation. The motor should kick up when it strikes a underwater object, saving the transom and avoiding situations like we have here.

I wonder if this motor had such a system, if it was properly in place and if the jack plate was built to withstand such an impact.


i think pretty much every OB has a release valve in the hydraulic tilt cylinders that allows the motor to tilt up if it hits anything. problem is that with that boat, if you hit something at WOT, stuff is going to break no matter what. No way to decelerate the engine from 60 mph to zero instantly without problems!
 

109jb

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Re: Check your outboard jack plates!

the guy inthe video was doing some speed trials so he wasn't the typical boater doing stupid stuff--he was a pro. But I see plenty amatuers trying it.

Oh, so he was a pro doing stupid stuff.

In one spot he takes his hand off the throttle at very high speed to wave to the camera. He gets the boat chine walking and rides it out several times. Finally on the pass where the accident happens he crosses a wake at an acute angle at full speed and it looks like the boat was chine walking before it hit the fist wake.

The video is irrefutable evidence that on that day the guy made reckless moves and almost paid the ultimate price. Pro or not it was stupid.
 

marine4003

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Re: Check your outboard jack plates!

the guy inthe video was doing some speed trials so he wasn't the typical boater doing stupid stuff--he was a pro. But I see plenty amatuers trying it.

On the photos, I suspect the motor broke loose and was hanging; the rescue folks heaved it on board for towing in. But a running motor coming loose can go in any direction despite its primary force being against the transom and down--just like an out of control car doesn't follow the road.

A pro....HA!! that was no pro, he was clueless driving that boat.No pro would drive a bass boat like that. Speed trials..more likely, stupid trials
 

NSBCraig

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Re: Check your outboard jack plates!

No that guy was not a pro!
 

QC

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Re: Check your outboard jack plates!

Funny how this thread has turned into a second episode of "dumb bass boater gone wild" . . . :rolleyes: :D

Back to the Jack plate deal . . .

No, it doesn't. It does exactly what you see - it ends up in the boat.
Seems counter intuitive to me as well. I guess if it hit something, boat stops, motor goes forward I could see it ending up in the boat, but how do you know this Jay? Not challenging you, just want to know . . . Sounds like another argument for an I/O . . . :eek: See . . . now we'll have another hijack :redface:
 

smokeonthewater

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Re: Check your outboard jack plates!

well think for a second about the forces at work...the boat is moving at say 50 mph.... all of a sudden the engine is free.... the prop driver the lower half of the engine forward while the upper half falls behind... the prop is now driving upwards but of course the boat is above it.... at this point there is way more drag on the engine than the boat so the boat outruns it.... now the prop is pushing the lower unit up and the control cables and wiring is acting like a big rubber band on the power head..... viola engine in the boat...... of course this happens in a fraction of a second
 

QC

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Re: Check your outboard jack plates!

Yeah, but prop torque would seem to matter at least a little . . . plus I am blown away that the cables would have any impact on 200 bhp . . .

Hmmmmmmm . . I smell a Mythbusters episode :eek: :cool:
 

oceansbreeze

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Re: Check your outboard jack plates!

well - I'm thinking they hit something, hard, and it snapped the motor off the transom, and it flipped into the boat... .... you can imagine consequences of that. I don't see how it couldn't happen? hitting the lower unit, would cause the top heavy upper unit to pop right into the boat... no?

of course what happened to the operator and passenger is only too obvious at that point
 

26aftcab454

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Re: Check your outboard jack plates!

well - I'm thinking they hit something, hard, and it snapped the motor off the transom, and it flipped into the boat... .... you can imagine consequences of that. I don't see how it couldn't happen? hitting the lower unit, would cause the top heavy upper unit to pop right into the boat... no?

of course what happened to the operator and passenger is only too obvious at that point

I dont know how much thrust a 200 hp motor makes ( 1500lbs???)but I can promise you its alot more than the weight of the motor.
1.-The lower unit strike an object at speed
2.-motor pops up breaking free between the two jack plates
3.-boat de-celerates instantly(while the occupants fly out)
4. cables stop the motor from forward motion landing in the seat

bad news travles fast.:confused:
 

Genonbamagirl

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Re: Check your outboard jack plates!

Sometimes they walk through the boat if the transom fails completely but not likely in this situation. The aft portion would be chewed at least some and it looks quite clean. The rescue personel rigged a lift of sorts or just manhandled the motor up from underwater.
 

Genonbamagirl

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Re: Check your outboard jack plates!

well think for a second about the forces at work...the boat is moving at say 50 mph.... all of a sudden the engine is free.... the prop driver the lower half of the engine forward while the upper half falls behind... the prop is now driving upwards but of course the boat is above it.... at this point there is way more drag on the engine than the boat so the boat outruns it.... now the prop is pushing the lower unit up and the control cables and wiring is acting like a big rubber band on the power head..... viola engine in the boat...... of course this happens in a fraction of a second

Except.......big bass boat engine is trimmed way out at high speeds so is in effect pointing downward and if freed will dig in the direction pointed (due to the weight of the engine being a somewhat stabilizing factor). I'm thinking they hit something, broke the frangible aluminum jack plate and got tossed in the water while the moater dug around underneath for a (short) while until starved for o2.
 

Genonbamagirl

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Re: Check your outboard jack plates!

Also - look at the little spindly rear fishing seat. The height does suggest that the engine could not have easily gotten past it without at the very least knocking the top half off.
 

smokeonthewater

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Re: Check your outboard jack plates!

well my point was that it doesn't matter which way it was pointed.. the engine will absolutely not go in a straight line... they do often land in the boat... they do also get knocked off..... I think the biggest thingg to take away from this is that things can go wrong very quickly at speed and a life jacket is not an ornament.... also a jack along with many other things can fail and preventative maintenance might save your life
 

26aftcab454

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Re: Check your outboard jack plates!

well my point was that it doesn't matter which way it was pointed.. the engine will absolutely not go in a straight line... they do often land in the boat... they do also get knocked off..... I think the biggest thingg to take away from this is that things can go wrong very quickly at speed and a life jacket is not an ornament.... also a jack along with many other things can fail and preventative maintenance might save your life

yes indeed
 

Genonbamagirl

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Re: Check your outboard jack plates!

well my point was that it doesn't matter which way it was pointed.. the engine will absolutely not go in a straight line... they do often land in the boat... they do also get knocked off..... I think the biggest thingg to take away from this is that things can go wrong very quickly at speed and a life jacket is not an ornament.... also a jack along with many other things can fail and preventative maintenance might save your life

Agreed.

Not to mention the fact that all that 1/2" aluminum is great until you consider that the critical point is the contact between the two sliding plates. The thing holding the whole shebang together is a contact point that involves four bolts and some washers....maybe a couple of square inches in most cases. I think a much better idea would be to borrow a jack plate, run it out, tamper, toy and tinker with it. Once the optimum setup is found, have someone fab a solid standoff with the correct elevation or make one yourself out of really durable materials.

Then........don't hit things with the motor.
 
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