ENGINE STALLS

[FSLOCUM]

I HAVE A 1990JOHNSON 120 HP. UPON RUNNING A WHILE, THE ENGINE STARTS TO MISS-FIRE AND STALL. ENGINE RESTARTS IMMEDIATELY.HAVE GOOD COMPRESSION, NEW PLUGS. WHAT CAN BE THE PROBLEM?

 

[fireman57]

Re: ENGINE STALLS

First off, welcome to iboats. Secondly, please lose the caps as it looks like you are shouting at people. The engine could be overheating due to a faulty water pump or a clogged water passage, could be losing spark due an electrical component like a coil or powerpack breaking down under heat and a load, or it could be fuel related such as starving for gas or an air leak in your fuel line. When it starts to misfire and stall squeeze your primver bulb if you have one and see if the engine picks up. If it does then check fuel system. If it makes no difference then when it misfires I would check for spark.

 

[FSLOCUM]

Re: ENGINE STALLS

Thanks, I'll loose the caps! Well I changed the wires and put in new spark plugs. Also the water pump in new and gasoline tank and lines are all new. Took it out over week-end and had to be towed again. Engine stalled out. Ttried starting it several hours later and it started right up. What is causing it to stall ?? Someone please help!!!

 

[fireman57]

Re: ENGINE STALLS

Did you check for spark when it stalled? Get a friend to pull one wire at a time when it acts up and see if your rpms change. If he pulls one (with very well insulated pliers) and the rpms do not change then you have lost spark to that cylinder. If rpms drop then that one is firing. Post results and we'll go from there. There will be better experts than I that will check this thread and help you out. Did you squeeze your primer when it started to stall?

 

[Brew2]

Re: ENGINE STALLS

Partially clogged or closed gas tank vent?