Merc 470 Dies after 40 min of running

[thenthfce1978]

I have a 78 Merc 470 4 cyl 165hp I/O engine that after 30 or 40 minutes of cruising cuts out like it has ran out of fuel. I can start the engine again but only idle for a bit before it cuts out again. Although tank is half full. I have replaced the fuel pump, line, and fuel sender. Cleaned all the filters. Also the cooling system has a new water pump and heat exchanger. Carb has a new rebuild kit. Can anyone point me in the right direction or tell me what could be the cause of this?

 

[DJ]

Re: Merc 470 Dies after 40 min of running

It could possibly be a coil (ignition) overheating.<br /><br />You can pick up one relatively cheap, for testing.

 

[hoot]

Re: Merc 470 Dies after 40 min of running

i second the coil suggestion. on second thought replace the distributer cap and rotor too, and points and condensor. if you do it yourself, it will be cheaper than taking it to a mechanic for an hour. usually running for this amount of time and shutting down is related to the ignition system. also if this happens again, loosen the gas cap and listen for a suction sound, you could be pulling a vacuum if the tank vent is plugged.

 

[magster65]

Re: Merc 470 Dies after 40 min of running

I've had the coil fail happen to me before... same symptoms as yours. I've had a bad condenser before as well. <br />When your engine dies, have you looked down the carb to see if there's fuel?