The new Briggs may be made in China. Our cases on Chinese Briggs engines suggest that initially they had serious quality control issues in the assembly plant, but this may have improved over the last year or more. However earlier this year Joe Carroll experimented with a recent Chinese Briggs engine and found that, with proper maintenance, it ran properly for 370 hours - but was then worn out. See this thread:
https://www.outdoorking-forum.com.au/forum/u...7178&Words=Chinese&Search=true#Post37281The old American Briggs engines seem to have lasted considerably longer than this - but 370 hours' use is a very long time for a suburban lawnmower.
I have a high opinion of the Honda GX120, but a second hand engine may have problems, or may have been used commercially (which will eventually wear out even a GX120).
My personal choice of those options would probably be none of them, and I'd look for a GX120 that had some silly tuning problem that had caused the owner to despair and sell it. However when you do that, you have to be ready to make the necessary repairs however complex they turn out to be.
