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johnson 1994 150hp ocean runner fuel pouring out of front of carburetors

eddielk

New member
I have Johnson Ocean Runner 150 Vintage 1994. It won't start and when I crank it, fuel flows out of the front of the carburetors ( all six). With starting fluid it pops and runs for a very short time. The mechanic is stumped. We disassembled one carb and it looked clean. reassembled it and tried to crank again and it flowed fuel out the mouth just like before. The fuel from the carb seems to have a lot of oil in it.

The mechanic feels that it may the the primer which is operated by the key and the red lever on the front of the engine. When you push in the little button on the air valve on the primer, there is no pressure.

Any ideas?

Mod No.: J150EXEOM

Eddielk
 
Re: johnson 150 ocean runner fuel pouring out of front of carburetors

Maybe the red lever is turned and in the " manual on position " ------------------Fuel pouring out the carburetors usually means stuck needle and seat ( float valve ) and requires cleaning / replacement.-------------Strange that all six would be bad --------------so check that primer ( block it off if you have to ) for a test.
 
Re: johnson 150 ocean runner fuel pouring out of front of carburetors

Hmmmm....another unqualified mechanic. And so soon!!!
Joe, you reading this?

Pumping the primer bulb with a leak you describe will show where the leak is. NO need to even try to run the engine. You are wanting the primer bulb to pump up, get hard, and not leak down. Your symptoms describe a situation where (I bet) the primer bulb never gets hard.

Oily fuel at the carbs is absolutely normal.

Fuel flow from carbs is always due to float levels set too high, sticking needle and seats, etc. Not likely all six as stated above. But that is what causes the fuel overflow. I suspect that it is not all six, and the diagnosis is wrong.
You can pinch off the fuel line leading to each carb bowl and see if the flow stops. That would isolate it from bowl problems versus primer solenoid problems.

Same with the primer solenoid. Pinch off the fuel inlet line to the primer solenoid. For testing you do not need it. Look for fuel flow to stop if the problem is in the primer system. Make sure the red lever on the primer solenoid is aligned with the body of the solenoid, and the pointed end is toward the bottom of the solenoid. That is normal run position.

Is this a brand new problem? Is it possible the carb bowls have warped on you? Even that should not cause the massive leaking you are decsribing, tho.

A qualified OMC mechanic should be all over this, and not "stumped", as it is an easy problem.
 
Re: johnson 150 ocean runner fuel pouring out of front of carburetors

Thanks for the feedback. I'll check out your suggestions. There really is fuel pouring out of all 65 carbs. The carbs look good. We disassembled one and serviced it and the situation didn't change.
 
Re: johnson 150 ocean runner fuel pouring out of front of carburetors

It does look like it is just one of the carbs, the top left looking at the foront of the engine. It gushes.
 
Re: johnson 150 ocean runner fuel pouring out of front of carburetors

Now it is making more sense. Pull the carb, remove the fuel bowl, and figure out why the needle and seat is sticking open.
When you think you have it fixed, orient carb in the right side up position, and blow thru the gas input line. Should flow freely.

Turn carb over, you will hear float drop, and blow again. Should not allow air flow.
 
i have the same model only newer 97 i have the same problem only one carb top left gas pours out only when running switched with carb below it started up same top left with problem .pump up the ball no leaks that elimanated the carb being the problem.now i will be checking the primer.got to do it by the book.i had replace fuel pump cause it pumped to much oil 2 months ago had no problems until 3 weeks ago any info would be great
 
well i just did primer test i pinched off primer line going to left bank didnt matter still pumps out fuel top left carb in running condition only.but it is spuratic after it runs a bit on high idle it will stop but come right back again .in gear same spuratic condition some times its worse or not but its there most of the time. should i be looking at the vapor pump float level after i shut it down milky fuel lays in the throat of the one top carb. have water sep filter also tested for water in system no water.the boat runs great less the fact that fuel is pouring out and fowling that plug .could there be air in the system that would make the fuel turn color.
 
i would pull off the feed line to that carb.get a portable gas can with a primer ball.pump it up it should stop leaking and ball should be hard. if still leaking needle and seat bad or float is getting heavy.dont no what float you have.brass or composition?you can make your repair and then bench test it with the gas can and primer ball should not leak on bench.we test all carbs like that before putting them back.hope this helps bcclew
 
You say fuel pouring out.....really? Raw gas dripping and running out the front?
Only when running.....hmmmm. And the primer bulb stays firm......hmmmmm.

OR, is it spraying out, misting, like it would if a reed is bad? Gotta have some clarification on exactly what you are seeing.

If it was a bad reed, that would explain why it still does it after you swapped carbs.

Milky fuel is kinda-sorta normal when it is very humid outside, AND you have choked it to be real rich. Like, if you put your hand over the carb throat, the fuel will collect there, and it will be milky.
Here in FL, I see milky fuel in the throat of carbs all the time.
 
at startup gas bubbles out the carb vent and the throat of the carb .in the carb it sprays an bubbles up through the high speed jet tube it all gets suck into the motor. no gas runs out of the carb throat untill you shut it off.when you shut it off the carb vent dumps more fuel as well. i checked the carb bowl for fuel it is full so its not pumping all the fuel out of the bowl. it all started one day at full throttle running great as usual then it would drop about 800 rpm that i know was a foul out of a cylinder sure enough thats when i saw the gas pump out the carb vent upon further investagation i saw the gas pumping in the carb. i tested the primmer as per my other post just the other day.trying to eliminate other possibilities.i thank you for any advice you can give me
 
Ok...I see now. I would have to suspect the float level first. But you say it is always the same LOCATION regardless of the carb body that is installed there. Very weird.
Are you absolutely SURE you swapped carb bodies....didn't accidentally put the same one back on in the same spot?
Could happen.

You are describing a leaking needle and seat, tho. Or a float that is sinking...something that would cause the gas to overflow.
I would do the normal debugging testing of the needle and seat/float operation. Use a piece of fuel line on the inlet to the bowl, turn carb over, blow, no air should pass. Turn carb upright, blow, air should pass.
Not much help here...i guess...

But I just re-read, and see that you are not the OP. Maybe if you started your own thread....this one is old.....
 
the gas is pumping out the carb vent when running.this is not needle & seat problem because it would leak when you squezze the primming ball.the original carb i had total rebuilt needle seat float the works still did it did not need it ,all parts looked good.then i replaced it with the other carb from below that had no problems.no mistake.no float sinking did that test your asked about even tryed to lower float so not much fuel would be in the bowl that did not matter.i been rebuilding carbs for over 20 years now.seems like alot of fuel pressure .whats an op and i did start my own thread nobody seems to be able to get a bit on this thing
 
What was the outcome of this problem? I have the same engine and it is doing the same thing. Rebuilt the carb, swaped it and still have fuel coming out the overflow. Did remove a vacume linethat is just above the carb and it stopped overflowing (but the engine dies) please
help!
 
I have same issue. Just found out there is a set screw behind the drain on the bowl. When I replaced the bowls, the new ones didn’t have drain plugs. Never check to see if it had the screw behind it. Thankfully I have all the old bowls. Going to check tomorrow and see if their missing. I’m hoping they are and this solves the gas pouring out the top left carb
 
You have to swap over the high speed jet ( orifice plug ) from old bowls to the new ones.----The high speed jet has nothing to do with gas pouring out of the carburetor.
 
You have to swap over the high speed jet ( orifice plug ) from old bowls to the new ones.----The high speed jet has nothing to do with gas pouring out of the carburetor.
it only seems to pour out right before it stalls or during starting. When I say pour out, I can literally see it come out like a fountain. Only the top left. I replaced the float,seat and needle. Adjusted float twice. Haven’t tried swapping carbs like the other guy on this topic. But I’m guessing I’m gona see the same results. Will up date after I put them screws in that I missed.
 
it only seems to pour out right before it stalls or during starting. When I say pour out, I can literally see it come out like a fountain. Only the top left. I replaced the float,seat and needle. Adjusted float twice. Haven’t tried swapping carbs like the other guy on this topic. But I’m guessing I’m gona see the same results. Will up date after I put them screws in that I missed.
Ok so old jet doesn’t fit the new bowl. The hole in the bowl is to small. Do I need to drill it out bigger or is it possible the aftermarket bowl doesn’t need it? Or do I have the wrong bowl?
 
well i just did primer test i pinched off primer line going to left bank didnt matter still pumps out fuel top left carb in running condition only.but it is spuratic after it runs a bit on high idle it will stop but come right back again .in gear same spuratic condition some times its worse or not but its there most of the time. should i be looking at the vapor pump float level after i shut it down milky fuel lays in the throat of the one top carb. have water sep filter also tested for water in system no water.the boat runs great less the fact that fuel is pouring out and fowling that plug .could there be air in the system that would make the fuel turn color.


Did you ever figure this problem out?
 
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