This has happened 3 times in the past year. On start up it will stumble and barley stay running. Dumping fuel in carb, black smoke, strong gas smell. It always happens within the first 10 seconds of startup when it does happen. I usually let it sit for 3 to 4 hours, and boom...cranks and runs fine. I have a 32/36 weber on it.

 

What's your running fuel pressure? Webers can only handle 4 - 4.5 psi max on the street, less off roading. You could also have a bad needle, seat or a sticky float.

 

I don't have a fuel pressure regulator. I need one. But it ran fine initially when I put the carb on for over a year.

 

You probably don't need one. Most people don't. Only wheelers or folks who modify the stock mechanical pump or install the wrong electric pump do.

FPR's don't tell you what your pressure is, a fuel pressure gauge does. If you're running a stock, mechanical pump with spacer with all of the factory lines properly routed you're probably not over 3.5 psi and likely 3 or less.

If it ran fine before and it sits a lot it sounds like a sticky float. If the float or needle freezes in the down position it will allow fuel into the carb unmetered. This can cause a vent condition. You can try running seafoam or some other petroleum solvent in your fuel. At worst, you'll need to pull the top off of the Weber and see what's up.