Logo
FULL SITE MENU

Johnson 150 oceanrunner 2 stroke running issues

N

Nkillian19

New member
I just picked up a new johnson 150, ran great for 2 long trips. On the 3rd trip it was having some issues with loosing power then gaining it back.
Took it home and did plugs on it.
Took it out again and it wouldnt get past like 1300rpm.
Limped it to dock and brought it home.
Seen that it was pouring a decent amount of fuel out of intake.
I have it running now and its idling fine, slight roughness to it.
When i take it on the water it has issues.
Boggs, doesnt want to stay running, etc.
Any help?
Its a 1996 johnson oceanrunner 150 v6 2 stroke. Looks like oil injection was bypassed and i now am running 50:1 ratio for fuel.
Video of running at idle : https://youtu.be/ciLyC2F6TLw
 
You need to track down several usual culprits. A V6 that has issues can sound just fine on the muffs but the back-pressure of having the lower unit the water will make the problems surface. So, using muffs trying to diagnose running problems can be misleading.

#1 Your vacuum warning sensor is disconnected (picture below from your video). You need to find the other end of this plug and get it connected. Once this is operational if you have a vacuum in the fuel system the warning horn will sound.
vacuum sensor.png

Did the primer bulb go flat when your problem happened? If yes, you might have a fuel restriction. When you remove the gas cap, do you hear a sucking sound? If so, your vent line on the fuel tank is not working and you're pulling a vacuum causing the fuel delivery problem.

#2 Check your fuel strainer. Just above the sensor I pictured is a white fitting with a 3/8" hose going into it. This is your fuel inlet and that white fitting contains a cone shaped strainer/filter. Remove that fitting and look for debris in the filter. If there is some there clean it and reinstall

#3 Spark. Use a spark gap tester and make sure all 6 cylinders will jump a 7/16" gap.

#4 Check carb settings. If you had fuel pouring out the front of the carbs you might have one or more float needles sticking open. If that's the case you'll need to rebuild all 6 carbs.

#5 Check your vapor separator tank. There are 4 screws on top of the VST and you can remove that to see if there is a buildup of gunk that might be restricting fuel flow to the pump.

When the engine bogs, does it blubber and stumble or does it just fall flat and die. Blubbering is a sign of over fueling or lack of good spark. If the engine just cuts out and dies that usually a lean condition meaning lack of fuel delivery.

KJ
 
kevinj said:
You need to track down several usual culprits. A V6 that has issues can sound just fine on the muffs but the back-pressure of having the lower unit the water will make the problems surface. So, using muffs trying to diagnose running problems can be misleading.

#1 Your vacuum warning sensor is disconnected (picture below from your video). You need to find the other end of this plug and get it connected. Once this is operational if you have a vacuum in the fuel system the warning horn will sound.
View attachment 23485

Did the primer bulb go flat when your problem happened? If yes, you might have a fuel restriction. When you remove the gas cap, do you hear a sucking sound? If so, your vent line on the fuel tank is not working and you're pulling a vacuum causing the fuel delivery problem.

#2 Check your fuel strainer. Just above the sensor I pictured is a white fitting with a 3/8" hose going into it. This is your fuel inlet and that white fitting contains a cone shaped strainer/filter. Remove that fitting and look for debris in the filter. If there is some there clean it and reinstall

#3 Spark. Use a spark gap tester and make sure all 6 cylinders will jump a 7/16" gap.

#4 Check carb settings. If you had fuel pouring out the front of the carbs you might have one or more float needles sticking open. If that's the case you'll need to rebuild all 6 carbs.

#5 Check your vapor separator tank. There are 4 screws on top of the VST and you can remove that to see if there is a buildup of gunk that might be restricting fuel flow to the pump.

When the engine bogs, does it blubber and stumble or does it just fall flat and die. Blubbering is a sign of over fueling or lack of good spark. If the engine just cuts out and dies that usually a lean condition meaning lack of fuel delivery.

KJ
Click to expand...

I found out that when the black and yrllow wire is connected, it will idle but then die after bout 20 seconds.
Wirh it disconnected itll idle roughly but stay idling out of water.
Took it for test with it disconnected and it idles crappy but went full roms untill it randomlu started to loose power then gain it again then finally died and wouldnt start back up. Got it home and now it will. Hmm
 
My primer bulb looses hardness but i dont hesr any sucking from the fuel fill port. The fuel strainer is clean and clear. The fuel has stopped pouring out since the issue of it starting to run bad. The vacuum seitch sits in loosly and i cant find the other end of connector.
 
Back
Top