hitting an underwater object

[just_crsn]

Looking for some advice guys.The story goes like this......my nephew and I took my boat out Saturday to do some fishing. The morning was beautiful but the fishing sucked...so we decided to move to another area. On our way there and traveling at WOT, we came to an all to sudden stop. In the process we were almost thrown out of the boat. (The boat is a 16ft flat bottom with a 25hp 4 stroke motor.) When we hit (unknown object at that moment) i seen out of the corner of my eye the motor tilting out of the water at the moment of impact and feeling the back of the boat seemingly coming out of the water as the bow was plowing down in the water. We gathered ourselve together and making sure the boat wasnt taking on water. I then turned my attention to the motor fully expecting to see no lower unit. To my surprise and relief it was still there with a rope tightly wrapped around the prop. I cut the rope away and checked to see if there was any leaking around seal...everything looked fine. I started the motor and put it gear.......everything seem to work. I told my nephew we need to see what we hit and to get that rope and what ever it was attached to out of the water. We find the rope and start pulling on it and pulling and pulling. Findly the object on the other end release from the bottom. We bring it to the surface....it was a 4 prong hook anchor.We take it to shore and throw it into the brush. My question is ....would the sudden stopping(shutoff) of the motor damage anything internally along with anything inside the lower unit? I did take it out the following day for about half of the day and there wasnt any sign of odd motor noises or fluid leaks. Would like to have some feedback on what possible problems i may have in the future.

Thanks guys

 

[Silvertip]

Re: hitting an underwater object

The rope itself probably had enough stretch that it acted as a shock absorber of sorts. I doubt you hurt anything although you might experience a spun prop hub down the road. If the engine suddenly begins to rev up but you don't seem to increase speed, that's because the rubber cushion that separates the hub of the prop from the outer blade area has come loose (the bond has broken). The prop can be repaired. For now I wouldn't be concerned.

 

[Jack Shellac]

Re: hitting an underwater object

I've wrapped rope around the prop a number of times, but not as violently as happened to you. It has never caused any damage so far, but it would pay to keep an eye on it for a spun hub as noted previously.

 

[5150abf]

Re: hitting an underwater object

I am an expert at hitting submerged objects, currently on my 3rd lower unit, I have moved to deeper water.

As Silvertip said other than scaring the crap out of you no damage done, it is prop strikes that will kill a lower, the engine stopped suddenly but I think it came to a soft stop.

Generally, if you didn't bugger the prop you are okay.

 

[Silvertip]

Re: hitting an underwater object

Just as a bit of a reminder, if anyone does hit a "solid" submerged object such as a rock and you have repaired the damage but have not been able to get the motor to start, before you tear it apart, pull the flywheel and check for a sheared flywheel key. That sudden stop stops the motor but as you were taught in physics class, an object in motion (the flywheel) tends to stay in motion so although the engine stopped the momemtum of the flywheel can be sufficient to shear the key allowing the flywheel to spin on the crankshaft which thows timing way off.

 

[coolguy147]

Re: hitting an underwater object

Just as a bit of a reminder, if anyone does hit a "solid" submerged object such as a rock and you have repaired the damage but have not been able to get the motor to start, before you tear it apart, pull the flywheel and check for a sheared flywheel key. That sudden stop stops the motor but as you were taught in physics class, an object in motion (the flywheel) tends to stay in motion so although the engine stopped the momemtum of the flywheel can be sufficient to shear the key allowing the flywheel to spin on the crankshaft which thows timing way off.

wow never thought this would happen

 

[Susquehanna Squid]

Re: hitting an underwater object

Another good practice is to run with the outboard unlocked from the transom, especially if you are unfamiliar with the water. My father and I were on the Bay of Quinte (Ontario) Walleye fishing one night (1 a.m.) and hit a Gill Net at WOT. It pulled the motor up out and slowed the boat immediately along with scaring the hell out of us. You don't expect to hit anything in 40 feet of water! If the motor had been locked I may have ended up going for a very chilly swim. Just remember, if it is unlocked, you have to be careful when you engage reverse as it will lift the motor out of the water.

 

[just_crsn]

Re: hitting an underwater object

Thanks guys for your responses. I will check my prop to see if was spun. I too had the motor unlocked and credit that little mechanism for minimal damage. I in a channel when i found this anchor........i think i will be wearing a PFD from now on.......that scared the crap out of me!!!

 

[TOHATSU GURU]

Re: hitting an underwater object

Here's some more potential bad news. It's possible to twist a crankshaft on all 4-stroke 25 models as they are pressed together....Usually loss of sleep occurs at this point until you try the engine again

 

[H20Rat]

Re: hitting an underwater object

**deleted**

 

[lowkee]

Re: hitting an underwater object

wow never thought this would happen

You mean learn something from high school physics?