Fuel oozes out of carb orifice a while after shut down

[Maxrevs]

2013 Husqvarna LTH154. It has a Walbro LMK carb fitted to a Kohler Courage 15HP [597cc SV470-3212, S/N 4304637623 build date 15/2/13].

Fuel is collecting inside the air cleaner housing and dripping on the floor - not a large amount, but concerning nonetheless. (I suspect it may be entering the engine too, diluting the oil.)

I tested the fuel cut-off solenoid and the plunger wasn't springing back up every time so I replaced it. But that hasn't cured the problem.

About an hour or two after shutting down the engine the fuel starts to ooze out of the carb.

I finally tracked down where it is coming from - the venturi on the left side of the intake which leads down to the float bowl.

I'm suspecting the float needle, but when I checked it under a magnifying glass it looked good.

Have any of you guys come across this problem before?

What do you think it might be?

Thanks for reading.

Regards,
Chris

 

[bertsmobile1]

The float valve is not stopping the flow of fuel.
Pull off the float bowl and clean out the carb.
Walbro have an excellent web sie with detailed instructions on cleaning their carbs.

 

[Maxrevs]

Re: Fuel oozes out of carb orifice after shut down

Yes, I'm convinced it's the float needle/valve. The carb is pristine clean having had carb cleaner, air and ultrasonic cleaning.

I've been searching for hours to find a replacement float needle/seat but I'm having no luck. All the parts diagrams I've seen don't list any parts or repair kits - just complete new carbs for £95 ($140).
[Walbro LMK, Husky part number 20-853-51S]

 

[ILENGINE]

Max the kohler part number for the carb repair kit is 12 757 27-s that should come with needle, possibly float, and the necessary gaskets. Sometimes you will get one that still won't seal even with a new float valve. I have in cases like that took valve grinding compound on the end of a cotton swab, and put it down in the seat, and turned it several times to remove any burrs. Have at time also use the old float valve to do the same thing. Just make sure to get it cleaned out well afterwards.

 

[bertsmobile1]

And same thing only different use a dremmel brush, in my fingers
If the float is really dark ed/ brown they need replacing as the amoun of fuel adsorbed into te plastic can be just enough to stop it sealing.
And the old favourite. a displaced float bowl gasket will do the same thing but usually it will cause a leak from the float bowl rim.

 

[Maxrevs]

Re: Fuel oozes out of carb orifice after shut down

Thanks fellas, this is all really good stuff. Very much appreciated :thumbsup: