Never had any luck with the Chinese Honda clone 6.5's, they are very cheap and fun UNTIL THEY BREAK DOWN. I purchased a couple of them new, put one on a yard kart and it lasted almost 2 months before it just quit. The other "knock off" I gave to a relative to put on a log splitter and worked fine untill it quit on him after a month. I Also bought a 13hp Honda clone but took it back and got a refund because I could never even get it to start. It was getting fuel, checked for spark, tried a new plug, not even starter fluid could bring it to life.
I have had numerous Tecumseh engines (6 and 6.5hp) on go karts, a bar stool racer and mini choppers and have never had ANY troubles year after year. Some people on the other hand swear by Briggs, The only ones I've ever had were used and one came on the first go kart I ever owned it was either a 2 1/2 or 3 1/2hp, was very old, tired and worn and I replaced it with a Tecumseh 6.5 which was years ago and is still on there today. The other Briggs was an Animal gas engine that is on a home made mini chopper which ran great except for the tillotson carb would get pretty finicky from time to time. The Briggs Animals are not cheap though.
For me, time does tell and has spoken loudly!
"You usually get what you pay for".