# Stalling Johnson 150



## MSLewis (May 15, 2008)

I have a 91 Johnson 150 VRO that I recently acquired. It doesn't want to hold an idle well - if left at idle too long, it stalls out (which makes getting it on a trailer fun!). This engine has had a lot of work done to it recently - new plugs, power pack, fuel pump, carb rebuild, fuel lines and bulb ... and the compression is good and even on all cylinders.

My initial guess is that the idle speed is a bit too low. I do not have a tachometer, but am tempted to tweak it a wee bit. Am I on the right track? Is there anything else I should look at?

It idles fine out of the water with muffs on - it'll sit there and idle all day long, no problem. In the water, however, is another story.


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## DeucesWild (May 15, 2008)

Make sure the engine's tilt position is as level as possible while at idle. This prevents the carbs from loading up with fuel causing engine to stall. I had a 89 GT 150 that would load up if you didn't keep the engine level while at idle. If it starts to load up, raise the fast idle arm a little till she clears up and that should burn off the excess fuel.


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## grasshopper (May 15, 2008)

When idling with muffs there's no back pressure on the exhaust coming out of the propeller. Try idling it up a little at a time if you put it in a drum of water or do it while at the lake that way it is like real life. Idle it up at the point where your cable goes to the carb brackets not at the carbs themselves they are synchronized together.


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## Doyle (May 15, 2008)

Also, just because you had the carbs overhauled doesn't mean that they cleaned the low-speed jets well (or they could be misadjusted).  Bad low-speed jets will also cause the same symptoms.


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## MSLewis (May 15, 2008)

Thanks for all the suggestions, particularly where to adjust the idle.

I did the carbs myself and know without doubt that they are clean. No adjustment on these jets.


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## spotman (May 16, 2008)

Did you clean the the small recirclation valves mounted under the carbs when you did the carbs?


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## ratherbefishin (May 16, 2008)

Is it oil-injected?  I had that same problem on an Evinrude and what was happening was the oil pump was pumping too much oil. When idling, the carbs would load up with oil and shut it down. Removed and bypassed the oil pump. No more problems, only have to mix the oil in the tank now.


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## MSLewis (May 17, 2008)

Spotman, if they were on the carb, it got clean.  I didn't clean anything on the engine itself - I'll check the manual and look into it. Thanks for the tip.

Ratherbefishin, yes, it is oil injected. Oddly enough, it sure does smoke at idle. I've been torn whether to bypass the injection system or not - since the pump is new, I'm comfortable leaving it as-is ... but if it's the culprit to the stalling, then bypassed it'll be! I wonder if I could set up a "test tank" to test the theory before I go through the trouble of draining the tank, etc.

I've been doing some research this morning and my "problem" may be as simple as an air leak on the fuel side, which would cause the VRO to mix in too much oil, which would cause a stall at idle with lots of smoke. I'll definitely check that one out, too.

Thanks for all the help, fellas! Please feel free to continue the suggestions and I'll keep y'all updated with the progress.


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## whitetailgitr (May 20, 2008)

sounds like your air/fuel mixture isnt right if you put a drum full of water under it you can tweak it from there in the same tilt position as it would be on the lake.... i dont know alot about outboard boat motors but i work on cars and that would be my guess either that or your idle speed


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## leoparddog (May 22, 2008)

My 1996 88hp Evinrude was doing something similar.  Turned out to be the primer solenoid (aka enrichment valve) that would normally only pump gas when you tried to choke it at the ignition switch.  It was pumping gas all the time into the carbs and the engine would drown at idle.  I turned the idle up b/c I didn't know what the cause was.

When I got it replaced I noticed a difference in the way the primer bulb felt when pumped.  When it was broke, the primer bulb would fill up but never get tight and stop, you could just squeeze and squeeze and all that gas would go through the primer solenoid and into the carb.  It gets tight now and stops when pressurized.


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## MSLewis (May 23, 2008)

Wow, that sounds just like mine. I can pump and pump and the bulb never gets tight. Eventually, fuel starts spilling out of the carbs. That may also explain what I feel is a fuel consumption issue. I've never had a big motor before, but this one just eats the fuel! Thanks for that tip.

I've tried to follow everyone's advice so far. I've pulled all six check valves from under the carbs and did find a bit of trash. I cleaned and checked them all. I'll definitely check that primer solenoid/enrichment valve.


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## MSLewis (May 26, 2008)

OK - I think I've discovered my problem! Let me see if I can explain this ...

There is a hose going from the fuel pump to a fuel rail that separates the main fuel trunk into three lines, one for each of the carbs. Also on this fuel rail is a small nipple that supplies fuel to the primer solenoid. This small nipple was apparently cracked near in two, because it too easily broke off when I removed the carbs.

Now, to fix this, I've got a few choices. 1) Replace with a good used one ($20) ... 2) Try to repair the old one (any ideas?) ... 3) Build a new one with brass fittings ... 4) replace with a new one (cost unknown ...).

Any other suggestions?


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## MSLewis (May 27, 2008)

*A real noob question ...*

I successfully repaired the old one. I used a brass insert from a compression fitting - it was the perfect size and length. I heated it up and melted it into the little manifold, which I had drilled out a little, then JB Welded all around it. It was in the hole tight when it cooled, and the JB Weld is added insurance. I think it'll work just fine.

I got the motor back together this morning and fired it up and it seemed to run great - very responsive to the throttle with what I feel is a bit more "vrooom."

I noticed, however, that I've got fuel dripping pretty steady from the top carb. I do have the motor tilted up quite a bit. Is this causing the bowl to overflow? Tilted down as much as possible, there seems to be less fuel spilling - a slower but steady drip. I can't put the motor down all the way 'cause the skeg would be in the dirt.

Is it normal for fuel to spill from the carbs if the motor isn't level, or do I have another problem?


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## Twenty five ought six (May 27, 2008)

> Is it normal for fuel to spill from the carbs if the motor isn't level,



No.



> or do I have another problem?



Yes.


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## MSLewis (May 27, 2008)

Oh, joy ...


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## MSLewis (May 28, 2008)

Well, that was an easy fix: The top carb had a speck of trash in the float pin seat. Once cleared out and reinstalled, everything works great. The primer bulb gets firm when pumped, no dripping fuel anywhere, and the motor seems to run exactly like it should! I can't wait to get it back on the lake and see how it performs!

Thanks for putting up with me and helping me out.


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## the HEED! (Jun 6, 2008)

coilpacks


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## SWbowhunter (Jun 6, 2008)

Stalling Johnson????
I recommend a urologist


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## whitetailgitr (Jun 9, 2008)

MSLewis said:


> Well, that was an easy fix: The top carb had a speck of trash in the float pin seat. Once cleared out and reinstalled, everything works great. The primer bulb gets firm when pumped, no dripping fuel anywhere, and the motor seems to run exactly like it should! I can't wait to get it back on the lake and see how it performs!
> 
> Thanks for putting up with me and helping me out.




next time you clean it if you soak it in some vat. chemical it will come out clean as a whistle just did it to mine bout 2 months ago


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