Steve Barker DLT wrote:

They're really the only way to go if you like getting the job done and
making it look good. And don't worry about the hydrostat oil change, it
only need to be done about every 500 hours. I think that's a long, long
time for a homeowner. We only change them in commercial service every two
years. And thats with 6 day a week use.

I didn't mean to imply that the hydrostat oil had to be changed
frequently, only that proper maintenance there is critical. The oil
level should certainly be checked each time you use the mower, since if
it runs out of oil and starts to suck air it can destroy the hydrostat
pump in short order.