Carburetor Leaking

HenryB

Petty Officer 1st Class
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Dec 8, 2012
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244
1998 Johnson 130. A lower carburetor is leaking gas when in the tilt up position, no leak in the down position even when running. It appears coming from the screw on the lower housing ahead of the high-speed jet. I?ve changed out the float and nozzle parts, I?ve doubled up on the ?o? ring seal at the screw, and I?ve looked for a visible crack in the housing, which looks OK.

The leak is pretty heavy but only when the motor is tilted up. It got me scratching my head.
 

Bosunsmate

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Apr 7, 2012
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Re: Carburetor Leaking

Doubling the o-ring can make it worse
Are you sure its not happening when tilited down? It could be draining into crankcase
Does it cause any running problems?
Did you change the needles for the float seats?
 

HenryB

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Re: Carburetor Leaking

I had just rebuilt the carburetor. Yes on the running problems after the rebuild. Rough idle. I've surmised it to be a flooded bowl problem. I took the bowl off and checked the float action by blowing into the gas inlet tube with the bowl inverted and right side up. I think the float/needle was sticking. I have reset the float/needle and checked and double-checked the action by blowing into the inlet tube. I will try the carburetor out in the morning.

I also went back to a single “o” ring. The leak apparently is from the vent hole just above the screw.

I do not know or sure that gas was leaking into the crankcase. It sure don't sound like a healthy situation. If the tilt up leak leak persists is it for sure that this is happening?
 

Bosunsmate

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Re: Carburetor Leaking

If its running rough then it probably is still doing it at tilted down. You can often see a lot of dark unburnt oil dripping down from the powerhead cowling and from under the prop area too
I guess you will find out in the morning if its fixed.
You could try adjusting it to close a bit earlier too.
 

HenryB

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Re: Carburetor Leaking

No joy. The same leak. I'm not 100% covinced the gas is coming from the vent hole, but a visual shows no cracks at the screw. I'm about to change out the brand new float, but my hope that will fix the problem are dim. After that it is switch carburetors. After that is replace the float housing/ the high speed jet, the intermediate jet, the "o" ring, a new float/needle, and anything else I can come up with.

Recently my boat decided to gush out the fill tube when filling. I changed out the vent line and so far no gushing. Then the pickup tube decided to go west (two complete gas siphons so far). Replaced the pickup tube. Then this.

My boat hates me. It has come up with the strangest problems just to get my goat. I don't know what I did to make it mad.
 

HenryB

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Re: Carburetor Leaking

Changing out the float was no help. Switching carbs did nothing. The same carb leaked. I did acertain that the gas leak is coming from the vent hole.

I'm now going to switch float housings to see what happens.

If this keeps up I'm going to get my old Machinist's Mate rate back, after sixty years.
 

HenryB

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Re: Carburetor Leaking

Well I have isolated the leaky float housing, but I cannot see what is causing the bowl to fill and leak. I hate to do it, but it seems time for a new float housing.
 

HenryB

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Re: Carburetor Leaking

A FOOT NOTE:

I found out that the float chamber I needed is no longer manufactured and all the big time suppliers cannot supply a lot of Johnson parts.

I found a supplier with parts in inventory for what I needed:

Roland Martin Marine Center

Call 863-983-2128
 

71Windsor

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Jun 25, 2008
Messages
286
Re: Carburetor Leaking

check your actual carb bowl the plastic bowls can warp and usually do. replaced mine when i got it about 12 years ago and again this year.
 

HenryB

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Re: Carburetor Leaking

I first heard of bowl warp a few days ago when talking with the Roland Martin Parts Department. My troublesome bowl shows no obvious warping. Is the warping obvious when it happens?

However, I came upon another “My boat hates me” trick my boat pulls on me. My high-speed jet had become loose and was just about to fall out. It may have been what was causing my problem (leaking when the engine tips up, but not leaking in the down position). Tomorrow I’m going to reinstall the old bowl to see what happens. Along with the new bowl I purchased a new rebuild kit and a pin that the float swings on, and new jets. They may go into my spare parts drawer along with a bunch of other good parts I changed out for no good reason.
 

HenryB

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Re: Carburetor Leaking

Well it's over. A new float housing did the job.

Warpage must have caused the problem, but not seeing any visual evidence of it, I think the warpage was partly due to my boat's warped disposition getting even with something I did to make it mad.

The loose high speed jet was just a mean spirited distraction. I think the jet could have fallen out completely and the motor would not have noticed it. Even with the warped float chamber and jet about to fall out the motor got smoothly up to 5500 rpm and held steady as a rock.

I hope the boat has had its jollys for the season.
 

71Windsor

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Re: Carburetor Leaking

if you take the bowl off and put it on a nice flat serface you might see if its warped. 2 of mine where obvious using a flat surface and the third i couldnt find any evidence of but it came back to bite my in the *** when i didnt order the replacement lol.
 

HenryB

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Re: Carburetor Leaking

Uh oh, three out of four went bad ?, not good news. Nobody makes the part anymore. I had to scrounge around looking for a marina with the part in stock. I’m getting too old for that kind of stress. My motor’s a ’98. My source had five on the shelf (four now). They cost $40 each new. A used one on Ebay is risky. Shipping two costs no more than one, think I will have two spares on my shelf very soon.
 

71Windsor

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Re: Carburetor Leaking

2 out of 3 for me i only have 3 carbs on my 150. Id stock an extra one for sure while you can. Mine seem to go bad about every 36 months but i also work my engines every day all year long. I am slowly converting mine back to aluminum bowls as I come across them. Plastic is generally in stock over at the BRP website (shop2.evinrude.com) however the aluminum bowls are not in production and coming across them is very rare. being as your engines 10 years newer then most of mine and probably doesnt see the usage as mine does id just have one on hand just in case. luckily i wont be ordering any more bowls your post made me take another look on ebay and wala found a complete set. so thank you i suppose lol.
 
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