+1 Briggs and Stratton, or Honda if your budget allows it.
Had this for two years. Couple of screws have come loose so had to retighten couple of times and could do with slightly more rugged wheels but does a great job of our large lawn.
Could be a Sumec Linhai motor in it.
Note some use honda engines others not.... not aure re this
Mountfield used to be a top mower brand. Has someone bought them out or just leased the name?