I have a exmark lazer z. Runs great but all of a sudden when I’m cutting it will just shut off after about 5 minutes. So I put the brake back on, turn off the PTO turn the key again and I fired right up. Cut for 5 more minutes shuts off again. Do the same thing but this time I keep the PTO off and let it run for 10 minutes. It ran the entire time no issues. So obviously something is up with the PTO but why after 5 minutes would it shut off?