RV Generator Maintenance Guide for Beginners

Generators need some care, whether in regular use or in storage between uses. Regular use is actually good for a generator, avoiding most of the pitfalls that can lead to frustrating problems. Conversely, using it once or twice a year requires an investment of your time to make sure it will run when you next need it.

There are three primary areas of concern for keeping your RV generator healthy:

1. Keeping moisture out of the wiring and internal components
2. Preventing fuel contamination and resultant clogs
3. Periodic engine service (oil, filters, etc).

Preventing problems Thru Good Maintenance

Good maintenance is both ongoing care and periodic actions as described in the owner manual for your generator. Some of the periodic items will be based on hours of operation and some on calendar time, and some on both (whichever comes first). The recommendations may seem very conservative, but they are intended to keep little problems from growing into larger ones.

The owner manual should also show you the location of filters, drains, filler plugs, etc.

Ongoing RV Generator Maintenance Tasks

1. Store and carry fuel in clean containers designed for the type of fuel.  Check for rust, dirt, insect nests, etc. before adding fuel. Do the same for the tank on the generator. [Does not apply to propane generators]
2. Discard old fuel.  If not badly contaminated, gas can be put in your car or truck tank – it won’t mind a small quantity mixed in with good fuel. Same for diesel if you have a diesel vehicle. If in doubt, take it to a fuel recycler.
3. Do not leave fuel in the generator tank or fuel lines during storage (anything longer than a couple of months).  Drain as much fuel as practical and then run the generator until the engine stops. [Does not apply to built-in generators that use the vehicle tank, but the use of a fuel stabilizer such as StaBil may help]]
4. Keep the generator clean, especially air-cooled models that rely on good airflow over the exterior.
5. Check oil level before every use and add as needed.
6. Check coolant level and add if needed [Does not apply to air-cooled models]
7. Store in a dry place whenever possible. Dampness causes long term problems that can sneak up on you!

Each month, run the generator for 30-60 minutes with a moderate load connected. The load should be at least 500-1500 watts to assure that the electrical generating components get warm enough to drive out moisture.  This is perhaps the single most important thing you can do to keep your generator healthy!

Periodic Maintenance Tasks for Your RV Generator

These usually include the following -

1. Change fuel filter (if present) periodically (see owner manual)
2. Clean or change the air filter periodically (see owner manual). Dusty conditions, dry leaves and such may require more frequent action.
3. Check and adjust the spark plug gap and clean if needed. Replace it per owner manual recommendation. [Does not apply to diesel generators]
4. Change oil and oil filter (if equipped) (see owner manual)
5. Clean the exhaust spark arrester per the owner manual recommendations.
6. If the generator has a drive belt, inspect and replace per the schedule in the owner manual
7. If the generator has a liquid cooling system, change per the schedule in the owner manual.

Common RV generator problems

A generator contains a lot of wiring, both a wiring harness connecting the components and the generator or alternator that actually produces the electricity.  Both of those consist of long lengths of wire tightly wrapped in bundles.

Condensation can seep into the bundle and eventually cause damage that results in a short.  In most newer generators, the components which regulate engine speed and voltage are electronic modules which can be damaged by water condensation or the connections corroded. When running, the engine heat drives out moisture and protects the sensitive parts, but a generator in storage needs to be kept as dry as possible.

Fuel contamination is a major source of small engine problems. Contamination can come from dirty containers or fuel that has been stored too long. The shelf life of gasoline is only 3-6 months before deterioration begins. It may be used longer than that, sometimes even 12 months, but it gets more and riskier as time goes on.  Furthermore, fuels such as gasoline and diesel can absorb moisture and become unusable (an advantage of propane is that it does not absorb water). It’s important to keep both storage containers and the generator fuel tank clean and free of contaminants.

Gas and propane generators use a spark plug to ignite the fuel, so it is a critical component in those generators (diesel generators have no spark plug). Spark plugs wear slowly, but can quickly get dirty if the engine isn’t running on a proper air/fuel mixture. Modern small engines usually have a preset air/fuel mixer, but attempting to run with contaminated fuel and change that enough to cause spark plug failure.

Any engine needs clean air and fuel to run, and most have onboard air and fuel filters to help with that. Dirty filters may be clogged enough to prevent adequate air & fuel from reaching the cylinders for combustion.  The engine also has oil for internal lubrication and an oil filter to keep that clean as well. Low oil level can result in a lack of lubrication and dirty oil causes excess wear.

Last, a clogged exhaust pipe or exhaust spark arrester can prevent the engine from getting rid of burned fuel gases.

Still don't have a generator? Make sure you read our guide on types of RV generators before making a purchase. And if you're looking for more information about caring for your rig, make sure you read our list of 49 RV Maintenance Tips.

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Written by Gary Brinck. Gary has been camping and RVing for 30+ years and has owned everything from pop-ups to Class A motorhomes.  He is active on multiple RV sites, a long time staff member at RVForum.net (over 60,000 topics posted!) and has authored several RV-related articles for magazines and websites.