onan is the best air cooled engine I have worked with, they are bullet proof. alot of the TM manufacturers market the kohler as an upgrade over the briggs, I don't see it that way, I haven't had that great a luck with kohlers, they don't start as easy, the sound of the starter is aweful, the ones I used ATE voltage regulators at $90 a pop, so far with my 18 hp briggs it hasn't given me any problems it doesn't burn oil starts easily and flat out just runs, I think its a better engine and I use it on an HX unit. I have a 16 hp briggs in an old used and abused cub XL that has at least 3500 hrs when the hour meter quit working, its still has very strong compression and runs great.