1984 johnson 140 h.p outboard, sputtering

[sikko97]

I have changed the fuel filters, the spark plugs and wires and it starts no problem it idles and will run at idle speed but when i give it gas she spits and sputters like its missing or something, cant get it up to speed. ANYONE HELP.

 

[Brew2]

Re: 1984 johnson 140 h.p outboard, sputtering

When was the carb last overhauled? (ie. cleaned, new gaskets, etc.).

Could be many things causing your problem, but I'd start with a good carb cleaning...espicially if the motor has been sitting for a while.

 

[jrs_diesel]

Re: 1984 johnson 140 h.p outboard, sputtering

I had (of all things) my 50cc 2 stroke scooter do that. Found I had a pinched fuel line. It was letting only enough gas come down for idle and not much else past idle. Mine would bog and sputter. It didn't die because it was getting a trickle of fuel, just enough to keep it sputtering. It would start up just fine though.

I suspect you are having fuel supply issues. I would check the carbs, lines, fuel pump, and tank.

 

[kenmyfam]

Re: 1984 johnson 140 h.p outboard, sputtering

Clean carb's and read ethanol poisoning in the top secret files.

 

[95cajun]

Re: 1984 johnson 140 h.p outboard, sputtering

i agree with kenny, anytime you have starting running power issues start with the basics, fuel - fire - compression. carbs are simple on these motors and I am by no means a boat mechanic. get the gumout carb cleaner with a straw, blow through every port orfice jet fuel line. pump the primer bulb to push out fresh gas through the fuel lines into the bowls look for the black crap. keep pumping til it goes away. make sure you have a very good filter in line, I preferr the glass with the little plastic screens. or buy a half dozen of the clear paper elements.

 

[emdsapmgr]

Re: 1984 johnson 140 h.p outboard, sputtering

Good comments regarding the fuel system. You might want to take a fuel sample to test for water in the fuel. It can run with water in the fuel, but it will have no power and act as you describe. If the fuel is old, get rid of it and add fresh fuel. Also possible you may have an ignition problem. Double check each spark plug wire to make sure all 4 are firing. It's easy and only takes a few minutes to eliminate ignition as a potential problem. An inductive timing light will show misfires or no fires when running.

 

[95cajun]

Re: 1984 johnson 140 h.p outboard, sputtering

Just a thought on water in the fuel....just because there is water in the fuel and you pump the tank, remember that water is heavier than fuel. They don't mix. You can pump the tank into a large container or several of them let them sit then pump the good stuff off the top...watch that you stop pumping before you get the large bubble of water and trash off of the bottom. Then pour the containers together and repeat till you minimize your waste. Just be very careful messing with gas in open containers, do it outside with good ventilation, no electronic devices including your cell phone. Also touch the ground or the side of the bucket or container often to prevent a static discharge. Use a primer bulb or siphen type operation no electric pumps unless they are way away from the open container and fumes.