Hour Meters, and Why Machines Are Serviced by Hours
Small engines, tractors, generators and boats are specified in running hours rather than dates. What an hour really measures, and how to track them without a meter.
Guide
Outdoor machines · OM-03
Generator Service and Run Log
A free printable generator log — monthly exercise runs, run hours, fuel, oil and filter changes for a standby or portable generator.
Download Free · no sign-up
One page. Choose your paper size — both versions are laid out identically, so neither one gets shrunk to fit.
Print it and write on it
Fill it in type and save
The fillable versions have real form fields — open them in any PDF reader, type into them and save. Printing help.
What this sheet is for
Make sure a standby generator actually starts when the power goes out, by recording the monthly exercise runs that keep it alive.
Who it is for
Anyone with a standby or portable generator — homes with unreliable supply, smallholdings, workshops and boats.
How to use it
- Record the specifications once, including run time at half load.
- Run it under load for around half an hour every month and log it.
- Change oil by hours as well as annually.
- Note fuel added and treat fuel that will be stored.
What is on the sheet
The layout is fixed at a size that fits both A4 and US Letter, so the A4 and Letter files are visually identical and print at full size on either. Rows are set at a height that an adult can actually write a date and a few words into with a pen — most printable tables are built in a word processor and never tested with one.
Questions
Why run it if I do not need it?
Generators fail from standing, not from working. Carburettors gum up with stale fuel, batteries lose charge, and seals dry out. A monthly run under load is what keeps a standby unit reliable.
What does 'under load' mean?
Running the generator with something actually drawing power from it, rather than idling with nothing connected. Manufacturers usually specify a proportion of rated output — check yours.
Read next
Why Small Engines Will Not Start in Spring
Stale fuel is why most mowers, strimmers and generators fail after storage. What happens inside the carburettor, and the two storage methods that prevent it.
Guide
Related sheets
Small Engine Service Log
Give every small machine in the shed the same maintenance record, using one sheet per machine.
OM-06 1 page
Outdoor Machinery Winterising Checklist
Do one pass through everything with an engine before the cold, so nothing needs a carburettor rebuild in spring.
OM-08 2 pages
One new sheet, most weeks
We are building this library out steadily. Leave an address and we will send the new sheets as they are finished — nothing else, and no more than one email a week.
Sign-up is not live yet — we have not connected an email provider, so this form is switched off rather than quietly collecting addresses.