140 HP Stalls under load, need advice

RonH77

Recruit
Joined
May 9, 2010
Messages
2
I have a 1986 model 140HP Johnson motor on my 19'Mako. It starts and idles fine. It runs great for a little while then just lays down and dies. It will start up again and then just runs slower and will not take the gas. I changed the water filter cannister and put a new clear inline filter in and a new primer bulb under console and topped off the tank. Then tried it and it did the same thing. I notice that the clear filter does not ever fill up fully and starts to empty as the motor is stalling making me think it is problem in the tank. This tank was replaced several years ago by the previous owner. I have tried removing the gas fill cap in case the vent was stopped up but it did not help. I tried a 6 gallon auxillary tank and ran the whole tank out with no problems so has to be problem between tank and motor. Wonder if I remove the water filter will this make any difference? It is older looking and wonder if there could be something clogged up in it causing this? Any ideas will help.
 

Camo Joe

Petty Officer 2nd Class
Joined
Apr 3, 2010
Messages
103
Re: 140 HP Stalls under load, need advice

There is something in the tank moving around clogging the inlet .............
 

Al-53

Chief Petty Officer
Joined
Jul 17, 2008
Messages
491
Re: 140 HP Stalls under load, need advice

the siphon tube may be blocked....take the fitting off and blow air down it...careful since you filled the tank....some have a screen on the end also....

some tubes come out...depends on the tank

Al
 

Overkill82k5

Petty Officer 3rd Class
Joined
Jul 29, 2009
Messages
78
Re: 140 HP Stalls under load, need advice

I had a similar thing happen with a Johnson 112 SPL. The problem turned out to be varnish buildup in the fuel lines breaking loose and damming up in the fuel line. All new lines, filter and carb/fuel pump cleaning fixed that issue.
 

RonH77

Recruit
Joined
May 9, 2010
Messages
2
Re: 140 HP Stalls under load, need advice

Thanks for all of the input. I installed new fuel line from tank to motor. Took pickup tube out of tank and made sure no blockage there. Old fuel line must have been collapsing. Runs great now. Thanks again. This forum is very helpful.
 
Top