Ignition does not turn boat off

[mmyers684]

Hello Everyone. I am new to boating this is my first boat. I am learning as I go. I am somewhat knowledgeable with engines and working on things. I have done engine work on a few bikes now. But on to boats. I have a 1989 Mercruiser 3.0L 181 CID engine. I cant read the serial number it is smudged. I have been doing work on the inside of the boat as well as the engine. I have run into a problem that stumped me. They key turns the engine on fine, but when you turn the key off, the boat just keeps running. The only way to turn the engine off is by touching these two wires together at the top of the engine. The only way I found this out is by messing with it. I know this probably isnt good for the engine. Do i need a new ignition or what could be the problem? Any help would be appreciated.

In an unrealated question, I want to give the engine a tune up. Is this the right kit i need? and does this come with new plug wires?

http://www.iboats.com/mall/partfind...&gd_poid=111653&gd_row=3&**********=868355352

 

[sltintexas]

Re: Ignition does not turn boat off

so are you saying it is running like normal..or is it dieseling? When it is dieseling it doesn't sound like a normal idling engine.

 

[Doernuth]

Re: Ignition does not turn boat off

Turning off the key should kill the current to the coil. Check the three position key switch.

Dieseling is a different issue and usually involves a timing issue.

 

[Alpheus]

Re: Ignition does not turn boat off

The only way to turn the engine off is by touching these two wires together at the top of the engine.

Doesn't sound like a dieseling problem to me if it shuts down when he grounds out the coil. (what it sounds like hes doing)

Disconnect your ignition switch and put an OHM meter on it. Just make sure you have no continuity when in the off position.

PS

Be careful when you are just touching random wires together. If you let the magic smoke out of some of those electronics, it can get expensive real quick...

 

[mmyers684]

Re: Ignition does not turn boat off

No, it is not dieseling, the engine just runs like normal, like the ignition was never turned off. I think it must just need a new ignition switch, but i couldnt find any other posts with this problem

 

[mmyers684]

Re: Ignition does not turn boat off

this boat is a nightmare. so it has never run well, i thought it was a combination of bad gas (as it was sitting for a long time) and carbs. I ran through the gas, then cleaned and adjusted the carbs. today i took it out. it still doesnt sound real good in idle. It knocks around. but it wont get past 1000 rpms in gear, even at full throttle. But if you put it in neutral and give it full throttle, it revs up fine. Im not sure wtf is wrong with it. Do i have a transmission problem here?

 

[Alpheus]

Re: Ignition does not turn boat off

Ignition problem:

With the key off measure the positive side of the coil and a good ground, if you see 12v there then your problem is that somehow the coil is remaining energized, ignition switch was a good place to start but now possibly you have a short near the switch or anywhere in the wiring harness.

WOT problem:

http://forums.iboats.com/showthread.php?t=295070

 

[bruceb58]

Re: Ignition does not turn boat off

Did you happen to recently replace your alternator?

 

[JustJason]

Re: Ignition does not turn boat off

a bad alternator would do that... pull the belt off it and try it to confirm.

 

[sethjon]

Re: Ignition does not turn boat off

Sounds like a short in the switch. Test it first to see if it has power when off, if not buy a new switch.

 

[Eric 3.7LX Alpha 1]

Re: Ignition does not turn boat off

People like to test the alternator by removing the positive cable off the battery to see if the engine is still running to see if the alternator is charging.

What that does is damages the diode built into the alternator which prevents the alternator from backfeeding the switched power wire to it. Giving you that exact problem you now have.

If that is the case you will need to replace or rebuild the alternator.

While the engine is off, Turn the key to run position and check the 12V switched wire to see if there is power there. (usually a purple wire), can check at the choke, Then move switch back to off and see if power is still there. *This is all with the engine not running*.

If that is working as it should it is the alternator that is the problem.

Let us know what you find

 

[mmyers684]

Re: Ignition does not turn boat off

thanks ill check it out later today