Hello , new guy from Ohio

I'm new the diesel engine. been around gas all my life. got a generator this week , it has a yanmar clone engine in it. it ran fine and now it pops out the air intake and back fires out the muffler with fire.. ran away 2 times . has to put a rag in the air intake. Im coming to you guys for help. its a older 6000SL generator. DEK F400 engine. Ill continue scanning the threads looking for help.. Thanks. MetalWorks Machine Shop on YouTube