Check the air filter. Knock out any dust. Ensure you have a clear air passage to the engine intake. Black smoke and a failure to run frequently indicates a very dirty air filter.
I borrowed my neighbors NH 7308. Ran for about 45 min. Died on me now I can't get it to run. It crznks, tries to stsrt then dies. I filled the tank. I bleed the injector lines. It blows black smoke. What do I try next?