Boat Turns Off

[applianceguy805]

I Have A 1977 Sea Form With A Ford 351 Motor And A Mercury 233 Outdrive. When I Put It In The Water It Wont Start. If I Pull It Out Of The Water It Starts Then Dies Once The Motor Hits The Water. It Works Fine When Hooked Up The The Hose. Any Help Would Be Greatfull.
I Found That The Trim Switches On The Side Of The Stern Were All Brittle And Falling Off With Bare Wire Showing. Everytime The Boat Hits The Water Around That Area The Motor Turns Off. Could This Be The Reason The Motor Turns Off Cause Its Shorting Something Out.

Heres a picture of the problem.
http://i258.photobucket.com/albums/hh258/805joedaddy/DSC00621.jpg

 

[applianceguy805]

Re: Boat Turns Off

i dont know crap about boats. how would i check something like that. does it sound like it could cause the boat to shut off.

 

[Don S]

Re: Boat Turns Off

i dont know crap about boats

How much do you know about engines in general?
Think about what is changing. Exhaust back pressure. Why does that stop your engine.
Carb adjustment, tuneup, timing, compression.
First thing I would do is a compression test, then a full tuneup, new points, condenser, spark plugs, cap and rotor. Then set the dwell to specs, then the static timing and the proper idle rpm. Readust the idle mixture on the carb and see what happens in the water.

 

[applianceguy805]

Re: Boat Turns Off

i have the prop in the water and it runs perfect everything is in the water that is suppose to. but once it gets to the certain point it turns off. i had the outboard in a big tub completley under water except the part im telling you about that wasnt in the water and it worked fine it. but everytime i put it in the ocean it shuts off.

 

[Surfdancer]

Re: Boat Turns Off

Is it shutting off when you try to put it in gear, like reverse to get it off the trailer? If this is the case, you probably have a problem with the shift cable and interrupt switch grounding the ignition. This is due to a stiff cable. This is a common issue with Mercruisers after some time, and is usually remedied by changing out the lower shift cable (which is a moderate PITA for a novice wrench).

Our Moderator has kindly put up a how things work list of threads, including the shift interrupt. http://forums.iboats.com/showthread.php?p=1930449#post1930449

Regarding the photo you posted, that should not affect your engine. It should only affect tilt / trim operation (limit switch or gauge sender). That is, unless you have other wiring issues, such as a poor ground from the engine to the battery (which is doubtful, since you can start the engine).

 

[jerryjerry05]

Re: Boat Turns Off

Unhook the T/T leads on the inside of the motor compartment.Then put it in the water.J

 

[chiefalen]

Re: Boat Turns Off

I've seen weird stuff happen when the leads are exposed on the trim sender.

And it ain't easy to run the wires back thru when you go to do it.

Like jerry posted disconnect the wires on the inside of the boat and go try it again.

You have the manual ? If not go to the top of the forum adults only download it.

You, and everyone on the forum is very lucky to have that resource, thanks to Don s.

Good luck keep us posted.

 

[Bondo]

Re: Boat Turns Off

I Found That The Trim Switches On The Side Of The Stern Were All Brittle And Falling Off With Bare Wire Showing. Everytime The Boat Hits The Water Around That Area The Motor Turns Off. Could This Be The Reason The Motor Turns Off Cause Its Shorting Something Out.

Ayuh,...

That's a Totally Seperate system,+ Shouldn't be connected, in Any Way, to the Igntion system....

 

[chiefalen]

Re: Boat Turns Off

Still runs thru the harness, my thoughts are find if thats the problem than see where in the harness the wires are stripped out shorting the ignition.

But i could be wrong have been many times before.

 

[applianceguy805]

Re: Boat Turns Off

well i cut the wires from the trim limit switch and the boat stayed running. i guess it was shorting something out cause not it runs perfect. thanks everyone for the help. now if someone else has this same problem you can have them look at there trim limit switch.

 

[Don S]

Re: Boat Turns Off

You may have fixed it so it will run, but you still have to fix the wiring that allowed the problem to exist to begin with. As several have noted, the trim limit wiring should not hooked to the ignition system in any way.
You have found a workaround, you didn't fix the problem.

 

[meesh]

Re: Boat Turns Off

You now know you have a short in your wiring harness. You need to find it before it shorts out something expensive or causes a fire. I would also replace those trim senders before you trim your lower unit to high while out running and ooops now another problem.

 

[applianceguy805]

Re: Boat Turns Off

so you dont think that bare wires in water from the trim switch was the problem. it was nothing but bare wires in the water. so if i took those off and it works perfect wouldnt you think that was the problem?

 

[Don S]

Re: Boat Turns Off

so you dont think that bare wires in water from the trim switch was the problem. it was nothing but bare wires in the water. so if i took those off and it works perfect wouldnt you think that was the problem?

As others have already stated, NO, that shouldn't have been your problem. The trim limit is not connected into the ignion wiring at all, anywhere.
Now rather something is hooked up wrong inside the boat or there is damaged wires inside that hook the trim to the igniion wiring who knows. But there is something really wrong if cutting those wires fixed it.

 

[applianceguy805]

Re: Boat Turns Off

i really didnt cut them im followed them to where they were hooked up and disconnected them. i dont know if that makes a difference or not. i looked everywhere else and everything looked good. this was the only problem i found in the wiring system. i know how to look for wires and test for shorts and i didnt find anything out of the ordinary. so what else could i do to check for if i checked all the wires and they all look good. the fuse box looks nice and clean no rust or anything.

 

[meesh]

Re: Boat Turns Off

If you have a switch only on the port side, follow those wires from where you unpluged them back to the trim pump. And if you have a switch on the starboard side follow those wires all the way back to your trim gauge. You've got to have a short somewhere, because those wires have nothing to do with the ignition system. It's a common problem, my wires were bare before I changed my senders and It never caused me an ignition problem. Also as I said earlier, without your trim limit switch working you risk the chance of someone raising your leg too high while tooling down the lake and if that happens it's going to cause you some major damage to your lower unit. Please find your short and then replace your trim limit switch and sender if you have both.

 

[chiefalen]

Re: Boat Turns Off

Ok everyone told you it got to be fixed.

How to do it is what you want to know?

Where to start ?

How about the main harness plug.

Pull it apart what do you see.

Then work your way back and forward, from the plug till you see where it stripped out.

It's grounding out, switch maybe, maybe wires, you got to do the work.

Good luck !