2000 Johnson 50 hp model J50PLSSM dead in water

[rascalsweet]

I have 2000 Johnson 50 hp model J50PLSSM on a pontoon boat; we took it out for the 1^st time today. It had the normal hard to start because you let it sit for 6 month of planning to take it out next weekend. It start ran poorly for a bit then got enough of the new fuel to make run normal for about 15 minutes. It lost power and died and wouldn’t start back. Let the kids fish then it started back, ran to about ¼ mile from boat ramp, then died again. We got a tow from some nice people from VA. The plugs look ok, only thing I can find wrong is probably the big thing. There was sensor (I think) melted/broke out of back of motor from the rear of motor in the upper left area. It has brown/blue striped wire going to it .

[Tater140]

i would clean your carbs. A quick check you can do is loosen the screw on the bowl of each carb and make sure gas is coming out. If you don't get a splash of gas out of them the float in the carb might be stuck. Try taking the plug wires off one by one and see if the motor changes idle speeds. this could help you find out if one of the cylinders is not firing. Check your fuel bulb and make sure it stays pumped up and hard. I don't know much about any sensors. Might do some research online on that one.

[Dutch552]

A picture of the sensor/wires you're talking about might help us out. I'd start with a carb clean/rebuild at a minimum if it has been some time.

[Archerguy1]

The sensor with the tan/blue wire is the temp sensor for the warning horn and system check gauge if you have one, sounds like the water pump quit working and the motor got hot and quit running, cooled off after you fished then over heated again. Warning horn won't go off if temp switch is melted.

[rascalsweet]

The sensor with the tan/blue wire is the temp sensor for the warning horn and system check gauge if you have one, sounds like the water pump quit working and the motor got hot and quit running, cooled off after you fished then over heated again. Warning horn won't go off if temp switch is melted.

I got a retired mech coming to fix the water pump and replace the sensor. That's what he thinks too. I'm not to sure that I didn't overheat trying to burn the bad fuel out, but it's 13 years old and had a weaker pump flow thank it should've had for a long time.

He checked it out, good compression, said the carbs were fine.