My 2022 Troy Bilt Pony lawn tractor starts and runs fine. I can engage the mower deck with no problem. But whenever I release the parking brake and engage the clutch, the engine bogs down and eventually dies. Doesn't matter what speed is selected, where the throttle is set, or what gear is selected, even neutral. I've checked the two drive belts and pulleys and all is clear. I'm at a loss.