Kohler CV460 16HP Lifter Noise

I have a Craftsman riding mower with a Kohler engine. The tractor is approx. 13 years old and has about 250 hours of run time.

After recently changing the oil and filter ( I've always used 10-30 as requested in the manual ), I began noticing a tapping sound.

The engine starts easily...without any hesitation. I'm assuming that this noise is a possible hydraulic lifter issue?

Any additives that can be added to the oil that would quiet this tapping?

see your other post for replies. And if possible just post once. It is easier to keep of track of questions and answers.

http://www.kohlerengines.com/onlinecatalog/pdf/tp_2339_d.pdf see if this manual helps, see troubleshooting.

You seem to care for your machine. Dirt is usually the culprit in stuck lifters. Some lifters are sensitive to going dry. Did the machine turn over or remain in an odd position?