Trouble Shooting & Need Help

flhunter27

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Mar 12, 2008
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I'm trying to figure out why my '91 150 Johnson stalls when given gas. It idles fine but cuts off when given gas. I need to know more about the antisiphon valve. I have two tanks that connect together then procede to the engine. I took off what I thought was the AS valve but it was hollow with no spring and ball in it. That piece came from a 90 degree elbow that came from the top of the port tank. Could this 90 degree piece be the AS vavle. It didn't seem to want to come off the tank so I let it alone for now. The motor was running great but then all of a sudden started doing this. Thanks to all who reply.
 

skynyrdcat

Petty Officer 2nd Class
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Mar 11, 2007
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157
Re: Trouble Shooting & Need Help

I'm trying to figure out why my '91 150 Johnson stalls when given gas. It idles fine but cuts off when given gas. I need to know more about the antisiphon valve. I have two tanks that connect together then procede to the engine. I took off what I thought was the AS valve but it was hollow with no spring and ball in it. That piece came from a 90 degree elbow that came from the top of the port tank. Could this 90 degree piece be the AS vavle. It didn't seem to want to come off the tank so I let it alone for now. The motor was running great but then all of a sudden started doing this. Thanks to all who reply.

Never had a double tank system, but I did have an 88 V-4 that had the AS valve in the 90degree elbow. I'm not sure why both tanks wouldn't have one unless it was replaced with a general fitting.
Can you elaborate on the performance?
Does it cut out as soon as you give it throttle or run for a few seconds (or more) then cut off?
Is the bulb empty after it dies or is it still primed?

How is the re-start?
 

ezeke

Supreme Mariner
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Sep 19, 2003
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12,532
Re: Trouble Shooting & Need Help

I think you should try using a portable tank with a different hose and bulb to help isolate the problem. From your description in the previous threads, it sounds as though you may find the difficulty in the primer bulb or one of the connections, but if you tried a separate setup, we could be sure.
 

cbavier

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Re: Trouble Shooting & Need Help

I think you should try using a portable tank with a different hose and bulb to help isolate the problem. From your description in the previous threads, it sounds as though you may find the difficulty in the primer bulb or one of the connections, but if you tried a separate setup, we could be sure.

If this doesn't work check your fuel filter. If it runs fine with an Isolated tank at least you will know it's not an engine problem. Vice verse
 

jtexas

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Re: Trouble Shooting & Need Help

Not unusual for someone to remove the AS valve & toss it, I'm not convinced it serves a useful function on an outboard anyway.

More important, does the primer bulb get hard & stay hard when you pump it up (get your minds out the gutter!)?

"stalls when you give it gas"...you mean it just dies completely?
Is that with the boat in the water, or on muffs in the driveway?
Will it restart?
Is the fuel line holding pressure?

If the timing don't advance when you give it gas, it'll fall flat on its face when you accelerate. Observe the timer base while someone advances the throttle...it should move forward smoothly without sticking.

What's your idle RPMs?
Could just be it's idling fine on 4 or 5 cylinders, but fails when you put a load on it.
 

flhunter27

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Mar 12, 2008
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Re: Trouble Shooting & Need Help

Okay, Longer story shorter.... took boat out w/ portable tank and it ran the same. So it had to be the fuel pump, took it to the shop and they confirmed and replaced under warranty. They tell me they didn't get to river test my boat because they couldn't get it to crank. So I tell them i'm picking up my stinking boat. Took boat out yesterday and it ran like *&#@*! Would not get on plane at all, then would not even stay cranked. I took off the cover and saw gas dripping out of the intake manifold/ air silencer. I know that's not normal so I checked it out but my question is, Is there a gasket that goes of the manifold because mine didn't have one and is there suppose to be some gas there or not? Now obviously she'll go back to shop so they can get it straighten out, but I need the boat Thurs. and don't think I'll get it back in time if they get it. Any suggestions on how to repair and answers are appreciated.
 

tashasdaddy

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51,019
Re: Trouble Shooting & Need Help

if you have gas running out, sounds like the float needles are not closing. need more info on where you think there should be a gasket. yes, intake to block, yes, carb to intake,
 

jtexas

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Re: Trouble Shooting & Need Help

How did you conclude it "had to be the fuel pump"?
How did they "confirm"?
When you did your portable tank test run, did you use a new primer bulb?
Is the fuel line holding pressure?
What's your idle RPM's?

Not sure where the gas is dripping, but you originally said "The motor was running great but then all of a sudden started doing this." Gaskets don't just disappear - if it wasn't there before, it's not the problem now.

What kind of shop did you take it to that would just tell you it wouldn't crank & not try to find out why?
 

flhunter27

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Re: Trouble Shooting & Need Help

jTexas, I took the boat out w/ a completely different tank, bulb and hose the whole nine yards. She ran the same. I don't know what the shop did as far as testing but they just said the pump was bad and replaced free of charge because of warranty. The shops been in business for 40 years and everyone with a johnson recommends them. I don't know about the pressure in the fuel line. How do you check it, I will find out? The rpm's were around 800 when she was first fire up and i traveled out of the no wake and hit the gas but then she stalled. She would crank back up but wouldn't stay cranked.

Checked my service manual and the gas is dripping from the air silencer cover and theirs not a gasket on it. There is suppose to be one. My question would be is there suppose to be gas in the air silencer, there is a drain hole in the bottom right corner but how much gas should be going through there? I know thats not the problem but I saw the gas and was concerned.

As far as the cranking issue, the shop said in the morning she would fire right up but in the afternoon they took her to the river and couldn't get it to crank for 3 hours. Took it back to the shop and said there was no fire. Said he could stick his finger between the spark plug and boot and not feel a thing. Checked the timer base and said it was bad. So I was pissed because the last time I took it to them they said they couldn't get her to start regularly. So I went to pick it up the guy turned the key and she fired up 3 times in a row. Wasn't giving them 400 bucks when I have never had a starting problem. Thanks for the reply and help!
 

iwombat

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Re: Trouble Shooting & Need Help

There's supposed to be a gasket in the air silencer. Nobody ever replaces it once the silencer gets opened up though. It does just about nothing. Probably 90% or more of the motors out there don't have one. I know none of mine do.

If you've got gas leaking out there you probably have a stuck float. That definitely shouldn't be happening.
 

flhunter27

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Mar 12, 2008
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Re: Trouble Shooting & Need Help

Okay, still in need of some help. I'm in the process as we speak of trying to fix the boat. Took off air silencer and running it on the muffs. Gas is coming out of the bottom carb, at the two little holes in the center?, at a descent rate, so my questions is.. Is that normal or not? The top two stay dry as a bone. She ran great stayed at 900 rpm's and didn't do anything out of the normal but I don't want to take it to the river and it just stall again. Yesterday I did clean all the spark plugs. Top two had a good amount of carbon build up, the middle two a little and the bottom two were pretty clean. Is that normal? Anyhow, all help is appreciated.
 

tashasdaddy

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Re: Trouble Shooting & Need Help

if you have gas running out of a carb it is not normal. stuck float for the 10th time.
 

jtexas

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Re: Trouble Shooting & Need Help

To my knowlege, fingers are not generally the recommended tool for spark tests, but sounds like your guy must know what he's talkin bout.

To see if the fuel line is holding pressure, squeeze the primer bulb; if it's firm, then you have pressure. After you pump it up, it should stay firm all day unless you disconnect it or run out of gas.

I replace that air silencer gasket when it gets too tore up to reuse. I bought 4 of 'em 5 years ago and still have 2. When my inventory depletes I'll think about discontinuing that item. The drain at the bottom should have a hose to scavenge engine oil that usually collects on the airbox cover. But shouldn't be any gasoline. Carb rebuild (with new float valves/seats) will fix that.

It's been my experience that, when Tashasdad says do something, your motor won't run right until you've done it.
 

flhunter27

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Mar 12, 2008
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Re: Trouble Shooting & Need Help

Okay, took off carb to check the float. No nothing about them but everything appears functional. Manuel says something about a gauge, p/n 324891, to check the float position. I don't have a guage is there another way to test this? Everything was clean and moved freely? Any more advice? Thank You.
 

Big Bubba

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Re: Trouble Shooting & Need Help

FLHUNTER 27,

I just did my carbs on my 88 SPL V-4 Evinrude Model# E88MSLCER and I put in carb rebuild kits in both my carbs and the directions say to invert or basically turn the carb upside down and make sure the top of the float as viewed from the side is level with the carb body or float gasket mounting area, if I am making sense to you. Basically I checked all 3 sides the left side, the rear opposite side where the float hinges at, and the right side and made sure that the float was level with the carb body float gasket mounting area. I also had the carb up side down or inverted and I tried to blow threw the gas supply line nipple and I couldn't and that told me that the needle was seating correctly then I turned the carb right side up and tried to blow threw the fule supply nipple and I was able to blow threw it telling me that the needle is off seat and that fule could come inside of it. Basically with the carb upside down the float is level or parallel with the float mounting surface of the carb body itself and if you have to adjust the float adjust the metal tang with the float off the needle seat a bit until it is level and also move the float off seat then recheck to make sure the float is level. Hope this helps you out Bob. I also pumped the fuel bulb up before I cranked the motor over and she held pressure and no fuel ran out the front of the carb. I cranked my motor over and she ran great and ran smooth and evenly without any hiccups. Hope it runs that good in the water when I put her in when she warms up. Thanks Bob:cool:
 

Solittle

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Re: Trouble Shooting & Need Help

hunter - You can't usually tell if a carb is clean by looking at it. You need to dissemble it, soak everything overnight, blow out all passages with high pressure air, install the new parts from the rebuild kit, reassemble, adjust & test. They are easy to do. I think there is a FAQ on it pluse use the search function for how to's & tips.
 

jtexas

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Re: Trouble Shooting & Need Help

If you looked at the float valve and seat under a microscope, you be able to detect if they are worn, but that's not necessary; the leak is evidence enough.
 

wavrider

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Nov 26, 2007
Messages
543
Re: Trouble Shooting & Need Help

There are jets in the carbs that need to be sure they are clean.everything you are pointing to screams dirty carbs.

Machinists wire, small drill bits can be used to clean out jets, if you do not have the tool to remove the jets. some people remove them, some do not, be advised if you try to remove the jets and break it you will need to find new carb.

turn your carb upside down and look at your float, should be even with the body, this is how you set the float level, maybe a tad bit upward level to be on the safe side.

soak your carbs in cleaning solution, napa has carb cleaner in a gallon can, with tray, expensive but best around, ( i tried everything else before I paid there prices)

Get them carbs cleaned good, replace gaskets, install with new gaskets on the manifold, do a link n sync after installation, check your timing, faq sections has the directions for timing setting without running the engine.

If you do not have a manual get one, save you hundreds in repairs you can do yourself.

As stated before, if TashaDaddy's says you need to do something to get your engine going again, follow his advice, he is usually dead on the problem.

any more questions or advice come on back and someone will reply, remember you are the eyes and ears so what info you give will help in the replies.
 
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