I have had my TBoss 550 F (Linhai) for a year and a half. I've used it extensively and the only issue was the steering wheel screws loosened slightly. Big deal.
Updated 4/26/2024:
Been having some starting issues. The starter would stall then the engine would kickback against the starter with a bang. Was afraid that I would break the starter or damage the ring gear. So, I replaced the 300 CCA U1 Lead acid battery that was OEM, with a 350 CCA AGM U1 battery. That solved the occasional cold start stall and kick back against the starter. The OEM flooded lead acid battery is just too small. Works OK in my lawnmower, though. 😒
Issue resolved.