This link should help with the carb. Sounds like a clogged Main Jet/Nozzle.

Here is a link that might be useful: Link

The seat switch and its wiring is not causing your choke problem.

You don't mention which engine you have, but here are a few things to check.

If your engine does not have a fuel pump (i.e. is gravity feed), disconnect the hose from the side of the carburetor and see if you have a flow of gasoline. It should be a stream, not a trickle. If not, replace the fuel filter and try again. If still no flow, just go on and replace the hoses and shutoff valve (if so equipped). Also, look in the gas tank and see if there's anything in there stopping up supply hole.

If you do have good fuel flow, then you probably have one of two problems (or maybe 2 of 2). First, determine if your mower has a fuel cutoff solenoid. This will be a small cylinder, maybe an inch long, on the bottom of the carb, and will have a single electrical wire running to it. Turn the key switch on and you should hear a "click" from the solenoid. If you don't hear the click, then check the wiring. (The solenoid operates a little plunger that stops fuel flow within the carb; some Kohler engines - and maybe others - are equipped with it, and some are not.)

If there's nothing in the tank interfering with gas flow, and you have a stream of gas out the end of the hose that connects to the carburetor, and the solenoid clicks when the key is turned on, then you need to clean the caruretor. Cleaning is not difficult. If it's a Kohler with a Walbro carb, you have only to disconnect the fuel line and the solenoid wire, remove two nuts from the side of the carb, and pull it off. Then give it a good cleaning. You might want to put a carb rebuild kit (about $8-10) in, but probably a cleaning will do.

Let us know what you find ... I and others will learn from your experience.

... the fact that your engine does run eliminates the problem of a failed solenoid, so disregard what I said about that. I had a late-night brain freeze. Sorry. (BTW, you'd probably get more info if this were posted on the lawn and garden tractor forum.)

After reading the link from Bill, I am ready to plow into the carb. (except that it is really hot even under my shade tree here in North Carolina). Sorry about forgetting the engine Twelveguage, it is a Kawasaki. And it has a cut off solonoid. I will check fuel flow on my way into the carb.
I guess the lawn/tractor forum could have been better, but when I searched over there I didn't come up with anything and didn't scan much a few days ago about John Deere (although I see plenty now). Besides, the folks here seem really sharp and on top of their game and really ready to help.

Well, I removed the carb easily yesterday and removed the bowl and cleaned it out although it was generally clean inside. I blew it out with air but didn't see any clearly clogged areas. However, when I installed the carb, the engine ran well.
Thank you Bill and twelveguage for getting me into the carb.

I have read plenty about this problem, including people who brought it to the dealer 5 times and it was still not fixed. This is what I did about it:

When it ran poorly, I drove it up to my garage and took an air hose to the top vent on my gas tank and pressurized the tank. It ran better. It already had a new fuel pump and carburetor on it.

I looked at the fuel pump and found that it is a diagram that relied on the fluctuating engine vacuum to activate it. That is a very poor design.

After discovering the poor design of the fuel pump, I eliminated the whole pump assembly and threw it in the garbage. Then I wired a universal electric fuel pump to the ignition switch power. The electric pump was rated for 2.5-4psi.
After putting that pump on, I made 5 swipes that were 1/4 miles long mowing out the ditches on my dirt road, then I put it to the ultimate test by mowing down 3 foot tall weeds to expand my parking area. It held up. This was my confirmation that the problem is fixed.