hi, covering the basics. fresh gas, i would change the plug. when it stalls and won't restart for a time, if you have a spark tester, see if you have spark during that time.

spark tester is an extra plug held to ground. - a mini taser.

Gas is fresh,

There is a wire connecting to the carb. It is not an electric choke. Not sure what it does or if mine is working properly

hi. when was the carb replaced? you don't mention replacing the fuel filter. your first issue, having to mess with throttle to keep it running sounds carb, fuel related. the second, it shutting down and not wanting to start could be ignition (coil, spark plug). after i sent you that comment i looked at a couple other discussions on your mower. i googled "john deere lx279 hard starting, look through some of the discussions and see if something sounds familiar.

An actual spark tester looks like a nice tool to have.

Thanks.

Fuel filter is good, gas flows easily to carb

More info- there is a vent tube on the carb- fuel is pouring from it. so I'm thinking full bowl/stuck float? Carb is brand new but it's a cheap clone- OEM carb is $260 this one was $55.

I have had good luck with cheap chinese parts but the key word is luck.

good theory.
The mystery to me is how it just seems to resist firing.
When i fist got it with a fowled carb and non-working fuel pump i poured gas down its throat and it wanted to run and burn every drop.

so after you replaced the carb, it started and ran? and did a cut. now it won't start and is flooding? is the carb easy to get to. take the bowl off and see if there's any crud in there. have you ever been inside of a carb? take your old 1 and remove the bowl should be a 12mm just to get the feel. if you haven't done so yet, i would go get another spark plug just because they look good doesn't always mean they are.

Sounds like a carb issue , especially with the carb overflowing the vent . As 300' advised the inlet needle valve may be fouled with crud . So you have a online fuel filter ? If not you should , dirt from the tank may have entered your New carb . Also is your air filter new or clean ? Fouled and dirty air filter also will cause rich fuel mixtures . New plug is a must too as 300' recommended . If with new plug your spark is not bright blue your coil or ignition module may be weak , but I would verify plug and carb internals 1st .

It was the spark plugs !!!

In my decades of home car repair I have never found plugs to be a major culprit. If they looked OK they usually worked OK. But apparently, these plugs are subject to internal failure. New plugs and it's a new machine.

I am so glad I stuck it out with this beast, it is a joy to use.

glad to hear you got it going.