Engine runs while key is in off position

[jphoenig]

I have a 1996 Sea Ray Searayer F16 with a 120XR mercury sport jet. Serial number 0E146650. Only have the boat a few weeks now. First time out it started up fine with the key on. After running WOT for about 15 minutes, the engine almost cut off and was running like it was being choked. I switched the key off to kill the engine and it didn't shut off and actually idled fine and I was able to drive it back to the boat ramp as if there was no problem. Of course the tac and fuel gauges didn't work since the key is off. Now in order to get it started I have to switch the key on, press the switch to crank it and quickly switch the key off and it starts. I already tried a new ignition switch but that didn't fix the problem. Any help or suggestions are certainly appreciated.

 

[The Marine Doctor]

Re: Engine runs while key is in off position

There has to be a shorted wire somewhere. Either in the harness or right on the engine. Black/Yellow is the kill wire. Start there.<br /><br />TMD

 

[jphoenig]

Re: Engine runs while key is in off position

The ignition switch is a two prong switch and only has two red wires running to it. There is a black and yellow wire that runs to the switch on the dash. Pushing it up with the key on cranks the motor. Pushing it down with the engine running kills the motor. Any ideas?

 

[The Marine Doctor]

Re: Engine runs while key is in off position

So you lanyard switch is wired to start the boat? Do you not have a normal ign switch?<br /><br />TMD

 

[jphoenig]

Re: Engine runs while key is in off position

I believe it's a normal ignition switch. I got a new one from a local part dealer and tried that and got same results. I put the key in and turn key to the on position, press switch on dash to crank motor. Since it's a jet boat there is also kill switch that is located right next to the ignition switch that gets connected to the driver and when pulled it kills the motor. That works like it should. So does the switch on the dash that kills the motor when pressed in the down position. Hope this isn't too confusing. The owners manual doesn't say a whole lot about the ignition switch. Although the wiring diagram in the book is a lot different then what is actually hooked up to the 2 prong ignition switch.

 

[The Marine Doctor]

Re: Engine runs while key is in off position

From the sounds of it you do not have the kill wires hooked to the ign switch.<br /><br />Whether this is a bad thing or not..you can always turn the engine off with the other means.<br /><br />TMD

 

[jphoenig]

Re: Engine runs while key is in off position

I agree. So I guess what my question should be is how can I get it to run with the key in the on position so that tach and gas gauges work since it doesn't run for very long with the key on? Really runs good with the key in the off position.

 

[zzzzz]

Re: Engine runs while key is in off position

BAD GROUND TO IGNITION SWITCH !! we've got one out in the shop for repair-exact same thing,repaired ground=shuts off

 

[jphoenig]

Re: Engine runs while key is in off position

Would a bad ground cause it not to run with the key on and only in the off position? Cranks with the key on and not with the key off. Runs with the key off and not on.

 

[jphoenig]

Re: Engine runs while key is in off position

Also the ignition switch only has two red wires running to it. A two prong switch.

 

[zzzzz]

Re: Engine runs while key is in off position

it may not necessarily be at switch...check starter solenoid,battery,harness connections,etc

 

[jphoenig]

Re: Engine runs while key is in off position

OK, I'll check it out. My dad is an auto mechanic and he had told me probably a ground wire too. I appreciate all the help. Hopefully I'll find the gound wire that giving me the problem.