1984 Johnson 25HP

[blueboat209]

Hello

I have a 1984 Johnson 25HP 2-stoke.

My current issue is that when I start the motor I'm getting a sputtering at idle and sometimes a sputter then stalls. I thought it was the fuel line going from my fuel tank to the motor so I replaced it and still I'm having the existing issue. My next thought would be maybe the fuel lines inside the motor cover.

Another though would be my fuel pump is having a issue? If I put the motor in drive fwd/rev I accelerate the motor it doesn't really happen or it takes a while for it to start to sputter, though it doesn't stall.

Thanks! Let me know if you need any more information.

 

[blueboat209]

Have you tried adjusting the slow speed needle item #25
http://www.marineengine.com/parts/j...5ECRS&manufacturer=Johnson&section=Carburetor
Turn it all the way in clockwise to lightly seated then back out 1 1/2 turns, bring it up to temp in the water in gear and slowly find the smoothest possible slow rpms by turning in 1/8 turn at a time and wait 20 seconds keep going in until it cuts out then back out for a smooth idle then add 1/4 turn rich counterclockwise and center the knob stop to stop and just leave it there.

No I have not. I will give it a try and let you know what I find.
Also another question is what kind of psi should I see for compression for the cylinders?

 

[blueboat209]

anything above 100psi and even within 10% is acceptable but the higher the better the key being they are even. Also check your spark gap with a spark gap tester. It should jump a gap of at least 3/8 inch brite blue snap on both wires.

Thanks Ill try that also!