Have a Dixie Chopper Classic 3160 2014 model with a FX921 Kawasaki in the shop that we were doing a service on the mower. Heard the valves rattling and went to adjust the valves. I was amazed at the clearance it had on the exhaust valves. One was about .030 and one was .075 and it ran just fine. Found it was an early model engine and the heads were a poj. Needs new heads at the price of over $500.00 each. Wow over a $1,000. just for the head kits plus other parts it might need and Labor. Looking at well over $2,000. to do every thing he wanted done to the mower. They had a recall on the same engine where they replaced the heads and cam but it was on earlier model engines built before 2007. Might need to check with Kawasaki and see if they might do something about. Engine only has 345 hours on it.