What maintenance does a diesel or petrol generator need?

They must be maintained correctly if you have petrol, diesel or a dual generator. Not only to avoid damaging your generator but also to ensure that they are safe to use.

What do you need to do to keep your generator running?

Before any generator is used, check for safety, oil, fuel level and LPG hoses for any leaks. Petrol generators require maintenance after 8 hours, 50 hours, and 100 hours. 250 hours of usage and major service after 3 years, replacing fuel lines. A diesel generator needs daily maintenance, oil and filter changes after 20 hours, every 3 months and 2 years a major service, including replacing fuel lines.

Regular maintenance should be carried out before you use any generator, whether it is diesel, petrol, dual petrol, and propane. For routine maintenance, if you do not feel confident, I advise that you pay a qualified person to carry out the work, especially for the more in-depth services.

Before completing any maintenance work, read the manufacturer’s manual first. This will give you a time scale for the model. Plus, how to clean air intake, oil and fuel filters.

What should you do when you first buy a generator?

The first thing you should do when you buy a generator is read the manufactures instructions carefully. Understand the different components of your generator. Each type of generator is different and requires a different first running time. Instruction manuals will detail:

  • Check for damage
  • Safety precautions
  • Preparation of your generator before running
  • Warm-up periods before usage
  • Specific features: oil, fuel filters, voltage selector and where they are located
  • Storage requirements
  • Maintenance schedules
  • Fill the generator with oil
  • Fill fuel
  • Test run your generator

What is the maintenance schedule for petrol or dual propane generators?

Petrol generators need a similar time-scale maintenance schedule as dual propane and petrol generator. The only difference is ensuring that any LPG hose regulators and checked for leaks.

The maintenance time scale for generatorsUnleaded Petrol GeneratorDual fuel (Petrol/Propane) Generator
Every 8 hours or every time it is usedCheck oil levels
Clean ground, air intake and muffler
Check oil levels
Clean ground, air intake and muffler
Check the propane (LPG) hose for leaks
First 5 hours or breaking inChange oilChange oil
Every 50 hours or yearlyClean air filter.
Change oil if in continuous usage.
Change the oil filter if using it in a hot environment
Clean air filter.
Change oil if in continuous usage.
Change the oil filter if using it in a hot environment
Every 100 hours or yearlyChange oil
Clean and adjust the spark plug
Clean spark arrestor
Clean fuel valve
Change oil
Clean and adjust the spark plug
Clean spark arrestor
Clean fuel valve
Every 250 hoursClean combustion chamber
Check and adjust valve clearance
Clean combustion chamber
Check and adjust valve clearance
YearlyService by a qualified professionalService by a qualified professional
Every 3 yearsReplace fuel lineReplace fuel line
Replace LPG hose
The maintenance schedule for petrol and dual petrol/propane generators

What is the maintenance schedule for a diesel generator?

The time span for maintenance Diesel generator
DailyCheck oil level
Check the fuel and fill it if required
Check for oil leakage
Check battery liquid
Check air cleaner
check and tighten any loose engine parts
First 20 hoursChange oil
Clean oil filter
Every 100 hours or 3 monthsChange oil filter
Change oil
Change fuel filter
Clean air filter
Check and adjust valve clearance
YearlyService by a qualified professional
Every 2 yearsReplace fuel line
The maintenance schedule of a diesel generator

Does a generator need to be serviced by a qualified person?

At least once a year, you should have your generator serviced by a qualified engineer. This will ensure the safe running of your generator and ensure that it continues to work during its life span. For routine care, you can maintain your generator. If you do not service and maintain your generator, this will invalidate your warranty.

However, routine maintenance before, after, and as per manufacturers’ instructions can be carried out by yourself. Checking and cleaning filters and replacing fuel lines can be daunting if you have never used a generator before. If you do not feel confident with this, ask a professional to show you what to do and give a walk-through of the different steps. This will help build your confidence.

Related questions

Why are diesel generators more expensive to maintain than petrol?

Diesel generators are more expensive, and the material used is more robust, as the engines run at a higher compression ratio than petrol generators. Petrol generators have a lower compression ratio and use lighter material components.

Portable petrol generators are more widely used due to their lower purchase price. However, on average, their life expectancy is 5 years less than a diesel generator. Although petrol is more affordable to purchase than diesel, petrol will degenerate more quickly and is not as fuel efficient to run.

There are other options available other than diesel or petrol generators. There are dual generators, which have 2 different types of fuel sources such as petrol and propane or solar and mains charged generator. I prefer the solar and mains powered generator as there are no harmful exhaust fumes to worry about. Plus, you do not have to worry about sourcing additional diesel or petrol when it starts to run dry. Not sure of the type of generator you want to buy? Our article guide to purchasing a portable camping generator explains the purity of energy generated, how this can affect your electrical devices, and the importance of the dBS levels for camping.

What is the life expectancy of a diesel and petrol generator?

The general rule of thumb for the life expectancy of generators is:

  • Diesel – 20-25 years
  • Petrol – 15 – 20 years

However, it is also essential to consider other factors.

  • Regular maintenance – do you need a qualified person
  • Make and model
  • Warranty period
  • Stored correctly when it is not in use
  • Frequency of usage
  • Where can you store safely when not in usage
  • Where can you store when camping to avoid damage from the elements
  • Original cost but running and maintenance costs

It does not matter what type of generator you have. If you do not maintain them regularly and care for them during their usage, your generator will not last. It will break down and stop working, which will be a nightmare if it is during your trip.


I'm a single parent who loves pitching a tent and exploring the countryside at any opportunity. I am working with a glamping pod company and helping them to set up a family campsite in East Riding Yorkshire.

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