1999 Johnson 150 acting up

[plasticmaster]

I have a 1999 Johnson 150 that is giving me trouble. When I first launch the boat and crank it, it idles fine, planes off fine, and runs pretty good. Then, when I shut the engine off and say, fish for an hour, then crank it up, that?s when the problems start. It cranks, but has a rough idle. When you put it in gear, it stalls out. I have to keep it in neutral and slowly rev it up to high rpm for a few seconds in order to try to plane it off. Sometimes this rev up and put it in gear process goes on several times and it?s getting worse and worse. If I can quickly give it full hard throttle and get it on plane, it runs fine then until you shut it off for a length of time and then the whole process starts over. The odd part is the first time it?s cranked for the day, it does fine. The problems start after it?s been run and then is shut off for an hour or so. This is very frustrating. Does anyone have any ideas what?s going on? Thanks.

 

[fishboy7504]

Re: 1999 Johnson 150 acting up

I don't know what it's worth but my '91 Johnson 175 was acting darn near the same way. I ended up putting on a new coil. My motor and probably yours also has 3 coils. I took out the spark plugs and noticed 2 plugs on opposing banks did not appear to have been burning a hot enough spark. The coil that fed those two cylinders was the one I replaced. That problem was now solved, so according to Murphys Law, another problem has taken its place, and so it goes. Good luck.

 

[tashasdaddy]

Re: 1999 Johnson 150 acting up

i suggest you check for a fuel line link. it sounds like the motor is starving for low speed fuel. try squeezing the fuel line bulb till it is hard, the start.

 

[plasticmaster]

Re: 1999 Johnson 150 acting up

I think the next thing I will check is a fuel tank problem. I have a portable 5 gallon gas tank. I have a connector fitting in between the primer bulb and the boat's built in tank. If I disconnect the fuel line at this connector fitting and just stick the bare end of the hose down in the portable tank, would this be OK? The primer bulb would still be in between the portable tank and the engine. Would this be a good method to rule out a bad tank problem or bad anti-siphon valve problem?

The mechanic that worked on it the other day found that the anti-siphon valve was clogged, so he removed the ball from it. After I ran it and still experienced problems, I removed the nozzle of the anti-siphon valve and found trash lodged in it. I removed the trash and cranked it in my yard with the water hose, but have not tested it in the lake yet. Is it a bad idea to run it with the anti-siphon valve ball removed anyway? Thanks for the replies.

 

[plasticmaster]

Re: 1999 Johnson 150 acting up

I ran it yesterday with the portable gas tank and it ran perfect the first time. Then, I shut it off and let it sit for 30 minutes. Without changing anything, I cranked it up, still drawing fuel from the portable tank, and it had a rough idle and stalled out and shut off when I put it in gear. This repeated several times. Therefore, the problem is still there and the problem is not the gas tank or gas line going to the engine. I'm using a brand new primer bulb also. The problem has to be in the engine somewhere. Am I correct? Any ideas?

 

[croakerpoker]

Re: 1999 Johnson 150 acting up

ive been searching and found this thread. my '97 175 has been doing the same thing for a while now and i have tried a whole bunch of stuff with no results. did you ever figure this out?

 

[brentmann]

Re: 1999 Johnson 150 acting up

My 1999 Johnson is doing the exact same thing-starts up fine runs fine shut off to fish then start up rough idle keeps stalling putting it in gear. What did you find out!

 

[jonesg]

Re: 1999 Johnson 150 acting up

This could be heat soak, try letting it idle a while before shutting it down and pump the bulb up to introduce cold fuel to the bowl , and removing the hood whilst fishing. If that fixes the problem you need to find a way to get more air into the hood without allowing water.
I wonder if a bilge cooling fan would work.

 

[Chris1956]

Re: 1999 Johnson 150 acting up

I have the same issue with my '98 Johnny 150HP motor. My work-around is to idle it fast in neutral for a minute or so, and then put it into gear. It behaves pretty good after that.

Jones may be correct about the heat soak.

 

[EHouseHead]

Re: 1999 Johnson 150 acting up

I have a 2000 Johnson Ocean Pro 150 with the same problem. I also noticed a couple times that after I shut off the engine and trim it up a little oil ran out down the side of the motor from somewhere leaving me to think the oil return line might be the problem. I know that if that leaks enough it will cause your engine to run lean (stalling exactly like we are experiencing). The only thing I am wondering is why I would be able to get the boat to run fine after about 5 minutes of starting and stalling. It seems like once it is warmed up it does okay until I stop for a period of time and try to start again. Let me know if you have found out anything and I will keep you in the loop on my issue!

Thx,
DJ

PS. I also wanna add that when the engine starts sputtering like it is going to stall it makes a sound similar to if you were pushing the throttle by hand on the engine and what I mean by that is it sounds like its sucking in air making and then stalls.

 

[Faztbullet]

Re: 1999 Johnson 150 acting up

Do any of you smell gas sometimes after engine has been shutdown?

 

[EHouseHead]

Re: 1999 Johnson 150 acting up

Nope, no gas smell.

 

[cub48]

Re: 1999 Johnson 150 acting up

this may be just a thought, are there any gasoline stations around that don't
have ethanol in their fuel. I am a auto technician and years ago when auto's
had carbs the old dodges would boil the fuel in the bowl of the carb.we had a tester to check alcohol content.as alcohol boils quicker. as while it boiled it flood the engine and would be hard to start as the bowl would empty because of the boiling. when it was cold ran fine. might try changing stations if you can't find one without. as some may dump more ethanol in than they are suspose to. cub48

 

[jonesg]

Re: 1999 Johnson 150 acting up

this may be just a thought, are there any gasoline stations around that don't
have ethanol in their fuel. I am a auto technician and years ago when auto's
had carbs the old dodges would boil the fuel in the bowl of the carb.we had a tester to check alcohol content.as alcohol boils quicker. as while it boiled it flood the engine and would be hard to start as the bowl would empty because of the boiling. when it was cold ran fine. might try changing stations if you can't find one without. as some may dump more ethanol in than they are suspose to. cub48

yeh, that lower boiling point is what would cause heat soak, its not an engine design error, its the fuel.
Letting it idle after a run and pumping the bulb to fill the bowls with cold fuel before turning it off can help.

 

[EHouseHead]

Re: 1999 Johnson 150 acting up

ive been using ethanol free fuel