Is there anything to do to a DZ as far as the maintenance ? I mean, what has to be done if the engine runs fine (preventive maintenance) ?

My engine runs fine, starts first flip every time, has good power, is extremely reliable... I am very satisfied appart from fuel costs which are outstanding. Anywhay, my engine has got 24 gallons of fuel through and runs fine. Should I do something or don't fix it if it aint broken.

Thanks