1984 Johnson 70 chuga chuga

[idonthaveaname]

I have a 1984 Johnson that seems to start fine, and idle okay, but at first underway, if I push it, it stalls. If I coax...chuga, chuga, chuga..she will slowly kick in and then fly down the river, slow down/speed up etc. working perfectly. Stop, cool down, and same thing. I am thinking carb or fuel pump issues, maybe hoses? Your thoughts/experiences are appreciated.

Thanks,
Steve

[Joe Reeves]

That's usually a fouled carburetor problem, especially if the engine has been sitting awhile.

[idonthaveaname]

Thanks Joe. I'm thinking maybe I'll try some Seafoam to clean it out.

[patrick4266]

I had that same motor and have a 70hp -91 rude now. It is probaly like Joe said but could be, fuel pump,lines have a hole in them air in lines,unvented gas tank or a hole in the pipe inside the pick up tube inside the gas tank. I've had all those problems at one time are another. Since it's cheapest I would try fixing the lines first, then carbs, "rebuild" then fuel pump.

[idonthaveaname]

"unvented gas tank"

Bingo! I should have thought about that. Thanks! It's been a long time since I've used a portable gas container and I checked finding the venting closed. That should fix it. Still, I think I will run some Seafoam through it.

Thanks for the tips gentlemen.

Steve

[Bob_VT]

Depending on the "known history" of the motor...... I would really opt to cut the chase and just remove the carbs and do them right. Sea Foam is great stuff but I would rather take the carbs apart.

The other thing that was not mentioned was the quality of the fuel? Was it old and new fuel mixed? was the tank completely empty?