Boat started by itself and ran for 7-10 minutes out of water

[DK in Chicago]

So today my boat started by itself and ran for 7-10 minutes out of the water.
It happened while I was running to the store to buy fuses.

So...

1988 Mercruiser 3.0 sterndrive
(Boat noob by the way so my apologies in advance)

What do I need to do check / fill / inspect before I attempt to put her back in the water?

What do I need to look for once I get her back in the water and running?

Here is a little backstory on this craziness.....

Finally got it back from the shop and dropped it in the water. Started great and ran like a champ. Killed it shifting from forward to reverse. Lost all electrical to the dash and ignition, tilt worked fine. Threw it back on the trailer and called the shop to see if they had any ideas.. They said check to make sure the fuses are ok and make sure all the connections to the battery are tight. So when I was checking the positive connection from the battery to the starter it was a little loose at the starter so i grabbed the red cable and pulled it to the right to tighten it up a little and it started to crank over.....??? Is that normal? Anyway I backed it off a little and eventually figured out it was the ignition fuse under the dash. So my guess s it was left a little too tight and cranked itself?

Thoughts and help much appreciated. Hoping to be in the water this Sunday for Fathers Day.

DK

 

[Phantom_II]

Re: Boat started by itself and ran for 7-10 minutes out of water

Welllll...

First off, your impeller is now a molten mass of rubber inside its housing, so you'll need to fix that.

Second, 7 - 10 minutes is an awful long time for an engine to run without cooling. If you have exhaust flappers, those are probably destroyed.

What else, lemme see, warped heads, frozen piston rings, scored cylinders, seized engine altogether (you'll find that soon enough if it did happen) and various other nasties that happen from overheating.

At a minimum, I suppose I would try an oil change and a new impeller, start it up and hope for the best.

You might get lucky.

 

[CheapboatKev]

Re: Boat started by itself and ran for 7-10 minutes out of water

Battery cable must have crossed on the selonoid to make her turn over I'm thinking..???

Cable should be possibly re-routed so that there is no chance of this happening again...

But I dont get how it happened while you were gone, off the boat, at the store buying fuses..Did people tell you "Hey bro your boat was running?"

and yes as stated impeller in the lower is toast, water pump maybe as well, will need to be really really lucky that your engine could survive 7 to 10 minutes, a 6 seconds without water will cause damage, can only think what 600 would do


best of luck and let us know how you make out

 

[Bondo]

Re: Boat started by itself and ran for 7-10 minutes out of water

Ayuh,... Don't sound good,...

At the Least, the Impeller,+ the housings,... The exhaust rubber parts, shutters, couplings, etc...

I'm with CBK,.. You shorted the battery wire to the exciter stud...

Good Luck,... There's factory manuals for your motor,+ drive up in the Adults Only section of this forum,...

 

[DK in Chicago]

Re: Boat started by itself and ran for 7-10 minutes out of water

Just my flippin luck I guess.....

I park it at my in-laws and luckily they were home today. Called me and told me, so I had my father in law disconnect the battery because since the ignition fuse was blown that would have no effect.

When he shut it off it was still running. When I got over the engine compartment it smelled a little like burning and antifreeze.

Thanks for the suggestions. I'll look up how to change the impeller and oil and pray from there I guess.

Any other comments are welcome. I'm still puzzled as to why it cranks when I move that cable, or it moves itself.....

 

[wajajaja02]

Re: Boat started by itself and ran for 7-10 minutes out of water

a closed system the engine might be okay, we ran mine in a tub not realizing that the impeller was gone in the lower unit until we ran it on muffs and observed that the water was not flowing out the exhaust ports. no damage. we ran it up to operating temps.

 

[Phantom_II]

Re: Boat started by itself and ran for 7-10 minutes out of water

When I got over the engine compartment it smelled a little like burning and antifreeze.

Antifreeze?

If you have antifreeze, suggesting a closed cooling system, the outlook isn't quite as bleak.

Your impeller and housing, plus any rubber parts in your exhaust are still toast, but your engine had some coolant circulating. It may have survived.

As for the cranking part, if your primary power cable on the starter made contact with the coil terminal, it will turn over, and depending on the way your ignition system is wired, it will start.

 

[SeanMcl]

Re: Boat started by itself and ran for 7-10 minutes out of water

Sounds like the boat is possesed and wants to kill you. Stencil "Christine of the Sea" on her, and post an ad on Craigsli... I mean, iboats.com, fast.

 

[wajajaja02]

Re: Boat started by itself and ran for 7-10 minutes out of water

I had a very talented mechanic change my impeller for me the other day its heavy,and needs to be done precisely, its not a job for a handy with tools guy. You may be better taking your boat back to the shop, 12vdc can kill you when working on starter voltages.and amperage and the damage that maybe done needs to be checked properly before its terminal. Overlook some small detail and blow the engine.

 

[danond]

Re: Boat started by itself and ran for 7-10 minutes out of water

I had a very talented mechanic change my impeller for me the other day its heavy,and needs to be done precisely, its not a job for a handy with tools guy. You may be better taking your boat back to the shop, 12vdc can kill you when working on starter voltages.and amperage and the damage that maybe done needs to be checked properly before its terminal. Overlook some small detail and blow the engine.

No impeller is heavy, and most are not hard to replace. The one on my OMC takes about 20 minutes to swap.

12 volts won't kill you. Go grab both terminals of the battery in your car with bare hands. Nothing happens.

Overlooking a small detail does not typically blow an engine. Overlooking filling it with oil, on the other hand, which is not a small detail, does.

 

[IVAZ]

Re: Boat started by itself and ran for 7-10 minutes out of water

No impeller is heavy, and most are not hard to replace. The one on my OMC takes about 20 minutes to swap.

12 volts won't kill you. Go grab both terminals of the battery in your car with bare hands. Nothing happens.

Overlooking a small detail does not typically blow an engine. Overlooking filling it with oil, on the other hand, which is not a small detail, does.

The whole outdrive has to be removed on the Merc to get to the impeller, it is kinda heavy. I dont think 12 volts can kill you but they certantly can hurt you.
20 minutes for an impeller change is awesome. Is there access from the outside of the drive on the OMC's?

 

[wajajaja02]

Re: Boat started by itself and ran for 7-10 minutes out of water

I saw a mechanic burn off the three outside fingers of his left hand when he touched the wrench from the positive side of a battery post to the body of a car while wearing a wedding ring. 575 amps,. Put the lower spline in one tooth off and he trashes the out drive. Its simple to change the gear lube once u know how, right now he has a engine in perhaps major peril, not routine maintenance.
I would opt to do what I do best this time and let others do what they do better for me on this one.

 

[Lightnig]

Re: Boat started by itself and ran for 7-10 minutes out of water

I saw a mechanic burn off the three outside fingers of his left hand when he touched the wrench from the positive side of a battery post to the body of a car while wearing a wedding ring. 575 amps,. ....

Yes, thank you.

Volts don't kill you, the fact that it'll throw you across the room and the impact hitting something hard may be, but volts by themselves mean nothing. It's the amps that get you.

All it takes is as little as 100 milliamps (0.1 amp) - actual mileage may vary - across the heart and game over.

http://www.physics.ohio-state.edu/~p616/safety/fatal_current.html

 

[wajajaja02]

Re: Boat started by itself and ran for 7-10 minutes out of water

working in an engine well, pushing and pulling on the main positive wiring while keeping your balance, guessing what components are doing or not doing what on a marine engine, that may not work for several reasons due to the overheat ,electrical, issue just is not safe and may not be economical either as you may damage components

we had my engine running perfectly, then it quit, after the new impeller.. we determine that the carb was fouled. it is off and being cleaned.

 

[DK in Chicago]

Re: Boat started by itself and ran for 7-10 minutes out of water

Thanks for all the help tips and info on this one.

I took it back to the shop this morning and gave them the story. They have worked on this boat longer that I have had it in the water so if anything is crossed they were the last to touch it anyway.

I let ya know what they say...

DK

 

[DK in Chicago]

Re: Boat started by itself and ran for 7-10 minutes out of water

Actually when it happened the fuse directly behind the key (ignition), which is apparently the fuse for the ignition and the entire dash, was pulled out because it went bad which is why I was at the store getting fuses when it started itself.

As far as I know they said it started but I wasn't there so for all I know it was cranking and cranking repeatedly the whole time, but they said it started so who knows 4 sure. Either way kind of a bummer...

 

[mkast]

Re: Boat started by itself and ran for 7-10 minutes out of water

12 volts won't kill you. Go grab both terminals of the battery in your car with bare hands. Nothing happens.

Try that holding a wrench between the positive terminal and ground.

 

[danond]

Re: Boat started by itself and ran for 7-10 minutes out of water

Oh for chrissakes you guys when was the last time you were killed by working on your boat?

You're more likely to die driving your truck to the mechanic with the boat behind it than working on your boat in your own driveway. Don't discourage the guy from fixing it by pretending like he's risking his life to the nth degree by solving a self-starting issue.

 

[DK in Chicago]

Re: Boat started by itself and ran for 7-10 minutes out of water

Well.... Good news...

Just heard back from the shop and it ended up being a crossed wire from what I was told. The whole time it wasn't running after all, just cranking and cranking away...

So he moved the wire and secured it away, checked it over, ran it and all is well I'm told.

Thanks for all of your help and suggestions!

DK

 

[windsors03cobra]

Re: Boat started by itself and ran for 7-10 minutes out of water

So did you get a new starter or are you going to take your chances on the open waters with a starter that cranked until the battery was gone ? Possibly ten fricking minutes of straight cranking. TOAST