Typically you can tell it is operational by feeling the solenoid or listening for a click whilst turning the ignition to run. Once removed, you can watch it activate the same way. Know that the fuel cap must vent as well to allow fuel to flow.
The fuel overflow issue is common w/ these. It is either debris holding the float valve open or a defective valve. It is advisable to clean the fuel system, replace the fuel filter and replace the lines if they are deteriorated. It is also a good thing to install an inline fuel valve and use it as these carbs can prove problematic. Change the oil if there are signs of fuel in it.

That fuel solenoid just stops, or greatly reduces, the flow of fuel thru the main metering jet, it has nothing to do with fuel getting into the float bowl. You will generally hear a clicking sound when the ignition is turned on if it is working or you could remove it and see if the plunger works in and out as the ignition is turned on and off. It is to stop backfire (after fire actually) when the ignition is turned off when engine is running.

The flooding out was likely caused by the float needle valve having something under it, some foreign partial. You may have a fuel line that has deteriorated with flecks coming off inside. Does it have a fuel pump? If so, is it connected, is it working? Remove fuel line from carb and see if there is gas getting to the carb.

Walt Conner

Just to add a "fine print" detail to testing the fuel cutoff solenoid "on the bench". If you are testing the solenoid using a 12VDC source with the solenoid removed from the carburetor, the plunger valve MIGHT NOT "pull in" every time you apply current between the wire and the metal body of the solenoid. The reason is that when the solenoid is not threaded into the carb, the plunger valve spindle will be extended farther than if it were in the carb. This extra travel ensures that the valve end will make a good, tight seal to its seat in the main jet. You might need to push in slightly on the end of the plunger valve to get the spindle deep enough into the solenoid coil for the coil to pull in the rest of the way in. If it remains held in the retracted position with 12VDC applied, and pops out when you remove the current......the solenoid is good.

I have had to clean several of those solenoids lately. They can get gummed up with old fuel deposits. Ove gut had a year old machine, that wouldn't do much more than a few sputters. I removed the solenoid, and it was stuck. A quick clean-up and it was good to go again!

"Now I cant get it to even get gas to the carburetor."

Nothing to do with the solenoid.

Walt Conner

I unscrewed it from the carburetor, and, after charging up his battery it did move in and out while the key switch was turned from the on/off, so I am assuming it is good. The more I am out there, the more I see that this machine was really abused. Yesterday when he asked me to work on it for him it was just a simple "carburetor rebuild". Tonight, after I charged the battery all day so I could crank it, I find that it has no compression. It's an ohv engine and since valve adjustment was quick and easy I adjusted the intake to .004 and the exhaust to .006. Now it has compression again but I am too tired to do anything else with it tonite, I'll try again tomorrow, scared of what I might find. On one hand, it's a friend and I want to fix it for him, On the other I dont want to fix something that he'll just tear up again. I mean this thing has the deck all tore up and bent out of shape, oil and filters look like they have never been changed. I dont know, it's just not how I like to take care on my things. Anyway's thanks for all your help guy's, as alway's, I appreciate it !!!

Did you have the piston 1/4" past TDC when you adjusted the valves?

Yes Bill, I believe I did have it a quarter inch past TDC.

My fuel solenoid problem turned out to be a flaky connection in the solenoid wire. On my 16hp Briggs&Stratton Craftsman riding mower, the carb is on the left, the solenoid is on the bottom of the carb float bowl, and a two-terminal connector attaches to the solenoid. For me, the black wire is just s short pigtail to ground and the white wire goes under the engine and out the right side to meet up with the rest of the wiring harness near the key start. Over there on the right side was a connector from that white wire to a blue wire. That connection was intermittent. Checking the white wire at the solenoid showed just about 4 volts once, then nothing. Checking the connector over on the right side (the blue wire now) showed a good solid 12 volts with the key on. Just taking the connection apart and putting it back together a few times caused 12 volts to finally show over at the solenoid. Put the carb back together (I had taken the carb off and the float bowl off to see what that nutty thing was on the bottom of the bowl. Another one of those gadgets that sounds good to the designer but then causes headaches in real life I guess. Anyway, it started right up and I'll replace the connector asap to fix it for good.

chrisb, you are to be commended for locating the faulty connection. Regarding your stated intent to get a new connector: You should consider if there is really a "need" for replacing the existing connector with another new connector. The point here is that the faulty connection you found has already served, and outlived its original purpose. The connector was to facilitate an easy, OEM assembly line build procedure, and nothing more. Or think of it this way: How many times since you acquired the tractor, have you disconnected and reconnected that plug (not counting the last couple of days)? Go to an auto parts store and get a small package of crimp type wire butt splice connectors. Get the kind that have a heat shrinkable covering already in place. For the size wire you are dealing with you want to get BLUE color splices (for wires 14 AWG). Cut the wires as close to the OEM connector halves as you can get. Then, strip away about 3/16" to 1/4" of insulation from the end of each wire. Connect the wire ends together with a butt splice connector using wire crimping pliers and then use a butane lighter or electric heat gun to shrink the thermoplastic covering of the butt splice down to seal the splice. Your intentions (to replace the OEM connector with a new one) are good, but logistically speaking, replacement OEM connectors are difficult, if not impossible, to buy. Unless the connectors are essential for frequent, routine removal of an electrical component, just eliminate any faulty, corroded ones you find by using a heat shrinkable butt splice. If you find a defective or corroded connector plug in a situation where the wiring must be separated and reconnected often, of course you need to retain that configuration. But, if the connector is one that served only the OEM build procedure.....trash can it.