212 Wont rev all the way

I have a stage 1 predator 212cc with the governor removed and a silencer on the exhaust. I was riding around my neighborhood and it was running fine. I went to my house to take a little break. Started it back up and it didnt accelerate as hard as before. Like not even close. top speed was like 38mph before but now its like 22 and it revs like half way/ 3/4s id say. Worried I might've blown or broke smt lol. it ran fine till i turned it off, took a not even 5 min break, and started it again. Any solutions??
Oil smells like gas and it's kinda metallic. Guessing I destroyed smt. I have a warranty on it so I'm more than likely going to put the stock air box and exhaust back on and take the stage 1 jet off. And replace the engine