Muffler full of gas!

F

Florida

Seaman
Joined
May 21, 2007
Messages
63
This is a clarification of a post I recently made about my Kohler lawn mower engine. I posted that there was fuel gushing out of the air filter box. People replied and said that it could be the needle valve or a problem with the fuel pump if it is electric. Here is the update.

When I removed the muffler it had a quart of gas in it. I took off the carb and tested the float valve by blowing into the inlet. When the float was in the up position it stopped the air flow. I also found out that I have a pulse type fuel pump and an electronic fuel shut off valve on the float bowl. I tested the electronic valve with a 12 volt battery and it clicks and pushes upward so I think it works.

I ask about the dealer about buying a carb rebuild kit and he said it cost over 100 dollars and they do not sell individual parts to the carb. I think we have a communication problem here. He suggested that I just clean out the carb. How should clean this particular carb?
Thanks for the help





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Mntom

Mntom

Petty Officer 2nd Class
Joined
Jul 14, 2010
Messages
140
Re: Muffler full of gas!

If you have gas getting through the carb like that then the float is not functioning properly. It could be the float level is not set correctly or even a float that no longer floats. More than likely the float level is what is needs adjusting. When you blew through the gas inlet was the float level with the body or was it at an angle?
 
DECK SWABBER 58

DECK SWABBER 58

Lieutenant Commander
Joined
Aug 14, 2009
Messages
1,913
Re: Muffler full of gas!

You really need a carb kit with all the gaskets, o-rings, seals, etc.
They also usually come with a new needle and seat.

Then you completely disassemble removing any rubber and plastic
parts. Soak for a few hours in carb dip, any auto parts store will have
a small bucket. After soaking you can rinse with hot water (wear rubber
gloves) and then blow out ALL passages thoroughly with compressed
air.

Be sure and check float level, kit usually has specs and a little guage.
Also make sure float is not absorbing gas or has a hole in it making it
too heavy.

Good Luck
 
marlboro180

marlboro180

Lieutenant Junior Grade
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Jun 23, 2009
Messages
1,164
Re: Muffler full of gas!

Your needle valve does not need much of a reason not to close all the way in order for a situation like yours to arise.

A piece of dirt, fleck of rust, bits o varnish-( note the crusty white nature on the main jet, it should be shiny brass) whatever, can keep the needle valve open, when it should be shut.

The gas ran through the bowl, across the intake, down into the bore through the slightly open intake valve, out the partially open exhaust valve, and into the muffler. It would be a good idea to pull the plug , drain and vent out the top end, as well as change the oil as it is most likely contaminated by the gasoline by now.

I have found out ( the hard way) that installing an in-line fuel petcock is really a good thing to install when the gas tank is above the motor.

As far as cleaning, rebuilding, etc. the carb kits are pretty cheap. Get that gunk off / outta there somehow!

+1 on checking the float level and buoyancy.

A hundred dollars for a carb re-build kit??? (I have a bridge for sale , ask him if he is interested!) I have rebuilt quite a few carbs on small motors, and have only needed the kit twice, when the intake gasket got ripped while trying to peel it off. And once when I dropped the little spring that holds the valve to the float, and the valve, into the grass and could not find it.

my .02;)
 
j_martin

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Muffler full of gas!

That one's pretty ratty, but even in good shape that carb is noted for leaking gas when the engine's not on. With the tank over the carb, any time it happens it's going to wreck the oil at a minimum.

I put an inline fuel shutoff on mine. To shut down, I close the valve, let it run dry (drains the float chamber and leaves the needle valve hanging open) and then shut off the key.

Startup, I raise the hood, open the valve, check the oil (takes a few seconds) then start and run for the day normally.

I'd be pretty sure Kohler has a kit for it. Go to their site, model and serial number in hand, and find the number. Then google the number.

There's 2 shops within 5 miles of me that would likely have one in stock.

My 02
John
 
642mx

642mx

Lieutenant Commander
Joined
Apr 19, 2008
Messages
1,588
Re: Muffler full of gas!

Sounds like gas is getting by the float valve. Most float valves have a rubber tip that gets a small groove in it (from resting on the seat) and they simply won't seal anymore.

If its a metal tipped float valve, you can clean the valve and the seat with Mothers aluminum polish. Use a cotton swab (with polish) and a cordless drill for the inside of the seat. Just don't get too carried away.
 
bigdee

bigdee

Commander
Joined
Jul 27, 2006
Messages
2,667
Re: Muffler full of gas!

sounds like the electric shutoff valve failed as well. I would replace it or add a manual shut-off. It is not uncommon for a float not to seat completely...that is the reason they put the electric shut-off on this engine.
 
bigdee

bigdee

Commander
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Messages
2,667
Re: Muffler full of gas!

correction on previous post.....Contrary to what some people think, the fuel solenoid IS NOT intended to act as a "cutoff valve" to prevent gas from leaking through the carburetor when the engine is not operating. Nor is it possible for the fuel solenoid to prevent gas from leaking into the engine. The fuel solenoid only blocks the fuel from flowing through the MAIN JET of the carb (which is the major provider of fuel to the engine). The pilot jet (aka slow jet, idle jet, low speed jet) is still open and if the carburetor needle valve is leaking fuel into the carb bowl, the pilot jet will flow the gas right on into the engine.
Your carb is obviously fed by gravity (fuel tank mounted higher than carb) and the oil level is climbing because your carb is leaking gas into the engine.
 
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