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Garn
07-05-2011, 01:16 PM
The other night I was out with the family. My wife was driving the boat. She wasn't paying proper attention and suddenly found herself coming at the dock at a high rate of speed. She panicked and threw the boat (2007 Mobius LS - direct drive) into reverse going pretty fast which killed the engine instantly. Luckily she avoided missing the dock. My question is can putting it into reverse going that fast hurt the boat? It obviously caused the engine to die.

Thanks,

Garn

mnpracing
07-05-2011, 01:23 PM
if the RPMs were low it won't hurt it. If the RPM's were high (not at idle), then I've been wondering the same thing.

viking
07-05-2011, 02:54 PM
YES -
But you'd have to be going quite a bit faster than approaching a dock :)

http://www.youtube.com/watch?v=68AOltMu768

Garn
07-05-2011, 05:32 PM
She wasn't approaching the dock. She didn't see it until it was there. I"m guessing she was gong 25 - 30 mph when she threw it into reverse. Could that cause damage?

Garn

moombadaze
07-05-2011, 05:35 PM
It could, but since it killed the motor you might be lucky. May have to take a spin and see how it sounds and feels.

squeeg333
07-05-2011, 05:37 PM
I'm guessing there's a fail safe in the tranny that will kill the engine if you try to throw it into reverse from going forward at higher than idle rpm. I would imagine that could destroy a gear train pretty quickly if not. You're probably okay since it did shut the boat down.

Hoopskier
07-05-2011, 09:37 PM
I actually browsed through my transmission owners manual one time, when I was looking for a fluid specification. I recall reading a section in there regarding this type of incident- Going forward and then suddenly into reverse.

If I remember correctly, as this is from my '03 trans owners manual, that the transmission would be OK to go from Forward to Reverse in an emergency situation. Clearly, you wouldn't want to do it on a regular basis.

Check the owners manual if you have one. Otherwise check the fluid, put the boat in the water and try it. If everything is fine, I wouldnt worry to much.

yearround
07-06-2011, 01:08 AM
The other night I was out with the family. My wife was driving the boat. She wasn't paying proper attention and suddenly found herself coming at the dock at a high rate of speed. She panicked and threw the boat (2007 Mobius LS - direct drive) into reverse going pretty fast which killed the engine instantly. Luckily she avoided missing the dock. My question is can putting it into reverse going that fast hurt the boat? It obviously caused the engine to die.

Thanks,

Garn

maybe don't say it was your wife, just another person? i really don't have anything to add.

but i did here that Utah lake is pretty full and not nearly and dirty as usual. i had many great days there, but haven't been there for years. i remember falling in the places in middle of the lake then standing up in chest deep water.

mmandley
07-06-2011, 01:25 AM
The boat tranny is similar to the way a car trans is, it has a reverse gear that engages to the 1st gear. Our boats are only 1 speed but it works the same way.

Boat going forward and you pull the throttle from forward right passed nuetal into reverse can cause a lot of problems. Luckily the engine died or a fail safe shut you down or the same damage a car would have will happen, break gears In the trans.

But in a boat since you prop is the tires in your car you can be moving forward and put it in reverse with no issues. Almost all of us do it when docking by bumping the throttle forward and then backwards. The key is make that nuetral stop for just a second. This let's the trans idle before going into reverse.

There's absolutly no issue going 25 mph forward then going to idle for a second then to reverse. You will get a jolt a lot of cavitation and possibly a wave over the stern but mechanically it won't hurt the boat as long as you get the neutral stop for a second to allow the prop to stop sp Ning before it's put into reverse.

phospher
07-11-2011, 11:44 AM
There's absolutly no issue going 25 mph forward then going to idle for a second then to reverse. You will get a jolt a lot of cavitation and possibly a wave over the stern but mechanically it won't hurt the boat as long as you get the neutral stop for a second to allow the prop to stop sp Ning before it's put into reverse.

Yeah, if you don't want your trans to last very long. The damper plate will not last long with quick shifting. If your going 25 forward you better stop momentum and let the trans sit in neutral for a few seconds before going into reverse. When you come off plane your prop is still spinning forward, to then jam it into reverse causing an instant change of direction is not good! If your alignment is correct, it will spin for several seconds. Don't take my word for it, lift up the center floor and go for a ride. This is all info I've learned from a boat transmission specialist who regularly is rebuilding transmissions like ours because people do exactly what you described.

Garn
07-11-2011, 12:22 PM
Thanks for your replies. I took it out over the weekend and it seems to be running fine. I can't detect any problems. And Yearround, yes, Utah Lake is the fullest I've ever seen it. At the Provo Boat Harbor then entire south launching ramp is gone - under water. It's incredible.

Garn