Strange Carb Leak

[Jason1793]

Hi, I'm new to these parts and hoping one of the experienced members can point me in the right direction. I've done some searching online, but to no avail.

After bringing home a B&S power washer that someone else had given up on, when I went to start it, the pull ended after about 6 inches. Pulling the plug, gas ran out the hole - no surprise. Removed the carb and replaced the needle valve and seat as well as a torn gasket and damaged breather tube. When checking the oil, I couldn't get a good read on it, and when I emptied the crank case - oil the viscosity of gas came running out. Oil change. Put everything back together gave her a rip and it started right up - belching black smoke for a couple minutes. After shutting it down and attempting a restart - no go.

Left the washer overnight and things were fine until the next afternoon. Gas had started leaking from the carb. Pulled the carb and fuel came running out the intake manifold. Disassembled the carb, checked the needle valve and seat were ok and confirmed the float actually floated.

With the carb still off the pressure washer I connected up a fuel line and elevated fuel reservoir to the carb. After filling the bowl, fuel started seeping out a port on the filter side of the carb (circled in red in the photo below). What is this port for and why is it passing fuel!?

Thanks (in advance).

 

[bertsmobile1]

That is the bowl vent
Fuel is coming out because the float valve is not cutting off the fuel supply
pull the bowl off turn the fuel on and then move the float up
IT should stop the flow of fuel when to top of the float is parallel to the bowl gasket and that should still have 1/8" to 1/16" before the float hits the carb

 

[Jason1793]

Many thanks - I'm more familiar with 4 barrel Holley carbs ;-).
I'll open things up again this week, run your checks and post my findings ...

 

[slomo]

You have to pressure test the needle and seat at 7psi for an hour or more. Flip the carb over and test. Should be a cake walk for a Holley guy. Several videos on youtube about it.

Float needs to be parallel to the bowl mounting flange.

New parts require testing.

 

[Jason1793]

Ok, opened up the carb. With the needle and float still in place, I flipped it over and applied about 2psi air pressure to the fuel inlet and it does not hold. The needle is new, clean and smooth. Here's a photo of the new rubber seat ... thoughts?

 

[Jason1793]

Did some more digging - pulled the seat, and when I did, the perimeter was covered in white powder.
Looking down the hole - I've got some cleaning to do ...

 

[Tiger Small Engine]

Did some more digging - pulled the seat, and when I did, the perimeter was covered in white powder.
Looking down the hole - I've got some cleaning to do ...

Use valve lapping compound, a wooden Q-tip, and a drill if you can. Slowly clean up the seat, spray with carburetor cleaner and blow out with air compressor to get it clean. Test and should be good.

 

[Rivets]

Make sure you install the seat in the correct direction, yes it makes a difference. The ridges should contact the carb body and the smooth side contacting the needle.

 

[Jason1793]

So to carry one ... cleaned out the bore where the needle valve seat sits and got the deposits off the sides of the new seat. Pressure test - go! Reassembled everything, put gas in the tank and gave her a rip. The engine started right up and I proceeded to wash down the truck to test out the washer.

All was good for a couple minutes. Then when I would let off on the wand's trigger the engine would start to bog. About a minute later, the engine seemed to come to hard stop. Tied to restart, but it behaving like it had fuel in the cylinder again!? Pulled the plug and pulled the rip cord - no fuel, no resistance. Reinstalled the plug - same hard stop on the pull.

Decided to replace a couple high pressure water circuit o-rings because of leaks, and removed and lubed up the pressure relief valve in case that was holding up production. No change.

Removed the pull start mechanism and shroud. Pulled the plug again and reconnecting it to the high voltage boot rested it against the frame of the engine and gave it a rip - no spark.

In the photo below you can see the rusted flywheel under the Rust Check I've just sprayed it with to slow that down. Not being familiar with magnetos - it seems that's my next stop on You Tube ...

 

[Rivets]

First, you did not help putting that RustStop on the flywheel. Magnetic flux is not affected by rust, but the RustStop may cause problems. I would remove it, install and gap the magneto, do not attach the kill wire and check for spark. No spark, time to replace the magneto.