I have a lincoln power arc 4000 welder generator with a Briggs and Stratton engine, the problem I am having is that it will not start? When I check the spark plug it is always wet with gas. When I spray carb cleaner in air filter it will run for a couple seconds and then die back out. I have taken the carb apart and checked and cleaned it twice and still have the same problem. Any suggestions?

1) have you tried replacing the gas and making sure there is no water in the system?
2) What have you done to the spark plug when you take it out and it is wet? Dry it off and clean it or preheat the plug?
3) does it have a auto choke system on the carb?

1) The tank was empty and I just put new gas in it. The gas in the filter didn't smell bad or look like it had water in it. 2) I dried it off once and then replaced it with a new one and got the same results.. 3) No, I have to slide the lever over to choke.

What is the engine numbers?

Did anything happen to the engine before it happened? Storage? Something else?

How about the oil level sensor? That's always a possible problem.

Check oil. If OK bypass sensor.

I saw this earlier, but I forgot about the oil level sensor for generators.

Oil level is good, and I haven't checked it but I assume the sensor is good because it starts to run with carb cleaner. I usually start it up and run it a least twice a year, but do to health reasons it hasn't been started since Nov. of 08. I did try and start when I was able about 4 months ago, and that's when I found out about this problem.

Chek and see if you have spark.if not check off and on switch,check oil senser.check amuture coil

It has good spark.

Okay , sounds like you have a valve stuck ,check you compression.
This happens all the time because there's more detergent in gas than gas nowadays.

It fires right up when I spray carb cleaner in the carb? But, I will check comp. anyway.

Check your fuel.
Take a hammer handle held stick in in the tank pull it out walk away and stick a flame to it.sounds like your fuel is bad .if it poofs when it lights its good ,if it lights real slow dump it out and start over.you will have to drain the carb. Bowl aiso.

I will give that a try when I get home this weekend and I will let you know what I find out. Thank all of you for your help.