I have had my JD LX 172 14 HP, 38" cut mower for 17 years. I bought it used when it was about 3 years old. Kawasaki engine has never given me a day of trouble.
This weekend I am replacing a belt tensioner pulley/bearings. First real issue I have had since I owned the machine. I think it's pretty cool that I can walk into a local JD dealer and buy parts for a 20+ year old mower (of course the parts ain't cheap either).
Replacement for a similar mower with the Kaw engine is $3K