If this generator is primarily for backup when an outage occurs, all
this maintenance is unnecessary. I run my generator once a month for 15
minutes. I only replaced the oil once (after 50 hours). I have never
replaced the spark plugs or done any of the other things you mentioned.
On the other hand, if this is a continuous source of power, then these
things should be done by someone who is familiar with the unit.


---MIKE---
In the White Mountains of New Hampshire
(44° 15' N - Elevation 1580')