Engine runs for approx 1 Hour then cuts out on Full Throttle, will idle though

[Shearwater]

I have a 60 Horsepower Mariner. Used to be ex police rescue engine on freshwater, serviced before I purchased it 2 months ago. It has power tilt and trim. Year Unknown - mid 90's? Serial Number 9785743<br /><br />Now used on the sea. It is running without any problems on full throttle for about an hour then the engine dies, sometimes it will start again immediately but will only run on idle - it dies again when put back on full throttle. It usually sounds quite rough at this time. There have been times when I have turned the key and there has been no response for several minutes, as if the battery has been disconnected.<br /> <br />Then after 5-10 minutes it will run on full throttle but not for so long - just minutes. Then it can be difficult getting it to restart - when I turn the ignition the engine just turns over for a second or so, I usually have to wait around 10 minutes until it will start.<br /><br />I have tried running it on a seperate fuel tank and it is the same. The pee valve is running cool water through it. There are no alarms sounding. The vent to the fuel tank is open. the primer is hard.<br />Is there a thermostat overheating, coil, compression problems, please help, I am quite new to the world of boat engines so have a lot to learn.

 

[roscoe]

Re: Engine runs for approx 1 Hour then cuts out on Full Throttle, will idle thou

Re: Engine runs for approx 1 Hour then cuts out on Full Throttle, will idle thou

1993<br /><br />I suspect ignition problem.<br />Stator powerpack switchbox or coil.<br /><br />What you need is a manual that can walk you through the troubleshooting.