Need Help91 merc io motor cutting out

"Alright, i have a 91 merc cru

"Alright, i have a 91 merc cruiser with a v6 4.3 the motor starts great....it runs for maybe 5 sec then it dies....hit the key again and it starts right up again 5 more sec and it dies again. it sounds like the spark gets cut...not really all that familar with boats but alright with motors. oh the boat ran fine until a punk kid tried to hot wire the boat...now this starting running and dieing...any insight will be welcomed. oh the engine will rev in the 5 sec before it dies. just trying to give all the info i can. thanks in advance."

"Check for a circuit breaker o

"Check for a circuit breaker or fuse that goes to the dash or ignition switch. It may be on a bracket on the motor but it sounds like the ignition lead (purple wire at the dash, safety switch and coil) has no voltage. Is the lanyard on the safety switch?"

"the lanyard is attatched to t

"the lanyard is attatched to the safety switch, i even took it off and put it back on a couple of times. there is a purple wire that is at the dash, and it goes to the ignition switch. however in the wire schematics the purple wire and red wire are switched...i switched them and it does the same thing, i looked for a fuse couldn't find one. so if the purple wire has no voltage the boat will still start but not stay running? thanks for the quick response and the future help."

"The purple wire needs to have

"The purple wire needs to have voltage to energize the coil, choke thermostat, gauges, etc. If the gauges are dead, the purple wire circuit is the cause and the safety switch is between the ignition switch and the gauges.

The crank wire from the ignition switch activates the solenoid and the starter has a lead going to the coil so the motor will start and when the key is turned to ON, the purple wire should have 12V on it to keep it running. My guess is that the ignition switch or the ignition wire is bad- maybe it was cut when he was yanking on things. Work your way from the ignition switch to the coil, using a multi-meter set to DC Volts to find the cause."

I think the fuel pump is on th

I think the fuel pump is on the front of the engine on that one. There is a safety circut that looks at the oil pressure sender to stay happy after starting or it cuts the voltage to the pump. The punk may have shorted something in this circut. Watch the voltage to the pump and see if it cuts out after start.