Biennial Oil Change?

[UncleDave]

A rider takes what, 2-3 qts to change it. Every fall when you store it with new oil.

25 hours to the OP's question

Some change it prior to first run in the spring so any moisture accumulated over the winter goes out w the old oil.

 

[Hermann]

If synthetic is in the sump, two years no problem. Especially that it has a filter.

Mine has no hour meter and no filter, does that mean it doesn't matter

 

[Lubener]

Myself, I would follow a 50 hour change on the oil and 100 hour on the filter. I believe that is what is specified. I change my conventional oil every two years and the filter 3-4 years. 50 hours in a season is a lot of mowing.