Outboard great in neutral, dies in drive

[Ken Williams]

I have a 3cyl. 70hp 1980 johnson outboard. When put in water and drove 20mins to fishing spot motor ran great. After 1hour started motor and went to move, motor died when trying to power away. (motor started first time and idled perfect). This happened six times and I thought I would be stuck there. Motor started first time everytime and idled perfect untill I put in forward and tried to move away. Keept motor in neutral and reved engine using cold start lever. Reved-up perfect, put in forward gear and tried to acelerate, motor died. After five minutes started engine, put in forward and powered away. Drove for 15 minutes, everthing running great. Stopped and fished for 2 hours and the same thing happened again.Ambiant temperature was 27 C and did not have to use choke to start. Where and what should I look for to solve this problem ? Would apreciate any help. Thank you.

 

[JB]

Re: Outboard great in neutral, dies in drive

G'Day, Ken. It is possible that your engine was running on only one or two cylinders when it appeared to be running perfect without a load. <br /><br />It is also possible that your carbs are only getting enough fuel for idling, and when you ask for more, it isn't there.<br /><br />To determine which of these problems is occurring, pump your primer bulb when the engine is misbehaving. <br /><br />If it picks up and takes off, your problem is with fuel supply. Check the tank vent, tank pickup, lines (for air leaks), primer bulb, filter/water seperator and the filter on the side of the engine. Pull one of the carb feed hoses and put it in a plastic bottle. Turn the engine over. If you don't get strong spurts of fuel, overhaul your fuel pump.<br /><br />If pumping the primer didn't help, pull and examine your spark plugs. A wet plug has not been firing. Try replacing them all.<br /><br />If you still have a problem, get back to us and we'll troubleshoot the ignition system.<br /><br />Red sky at night. . .<br />JB