A portable generator spends far more time in storage than in active use. It’s during those idle months that the real damage happens: fuel goes stale, seals dry out, moisture creeps in, and the engine that started first-pull last season suddenly refuses to cooperate. The good news is that a handful of simple maintenance tasks can prevent nearly all of these problems. This guide walks through a practical, step-by-step process so your machine is always ready when you need it. The advice applies to all portable inverter generators, including the Gentrax range available from Outbax.
Essential Steps Before Putting Your Generator Into Storage
Allow a Full Cooldown Period
Never drain fuel or move your generator immediately after use. The exhaust, engine block, and muffler retain significant heat for 15 to 30 minutes after shutdown. Let the unit sit on a flat, ventilated surface until the casing is cool to the touch. This also allows oil to settle into the sump for an accurate level reading.
Clean the Exterior and Inspect for Damage
Wipe the housing with a dry cloth to remove dust, dirt, and fuel residue. Pay attention to air intake vents and the exhaust port — debris here restricts airflow or attracts moisture. Check the pull-start cord for wear or fraying. A quick visual inspection now saves troubleshooting later.
Confirm the Basics
Before walking away, check that the fuel valve is off, the spark plug cap is secure, and the unit is sitting level. If you plan to store the generator for more than a month, complete the fuel and engine maintenance steps below before the unit goes away.
Fuel System Care: Preventing Stale Fuel and Carburettor Damage
Drain the Tank or Add a Fuel Stabiliser
Stale fuel is the single most common reason a stored generator fails to start. Petrol begins to degrade within 30 days, forming varnish-like deposits that clog carburettor jets and fuel lines. You have two options: drain the tank completely, or add a quality fuel stabiliser to a full tank. Stabiliser extends fuel life to around 12 months and is the preferred approach if you want the generator ready at short notice — particularly for emergency home backup.
Choose Ethanol-Free Fuel
Standard E10 petrol absorbs moisture from the air over time, accelerating corrosion inside the tank and carburettor. Where possible, fill up with ethanol-free 91 or 95 RON unleaded before adding stabiliser. In Australia, ethanol-free options are widely available at most major fuel stations.
Run the Carburettor Dry
After circulating treated fuel for two to three minutes, turn off the fuel valve and let the engine stall from fuel starvation. This empties the carburettor bowl, removing the small volume most likely to gum up during storage. It takes under a minute and is one of the most effective steps you can take.
Engine and Component Maintenance for Long-Term Reliability
Change the Oil and Inspect the Spark Plug
Used engine oil contains acidic byproducts that corrode internal surfaces over time. Changing oil before storage — not after — protects the engine while it sits. Use the manufacturer-recommended grade (typically 10W-30 in Australian conditions). While the kit is out, remove the spark plug and inspect it. A light tan electrode is healthy; if it’s black or oily, replace it. A fresh plug costs a few dollars and eliminates a common cause of hard starting.
Clean or Replace the Air Filter
A clogged air filter restricts airflow, reducing performance and increasing fuel consumption. Remove the filter element and tap out loose debris. Foam filters can be washed in warm, soapy water and lightly re-oiled. Paper elements should be replaced if visibly dirty. Store the generator with a clean filter fitted so it’s ready to run without preparation.
Battery Care for Electric-Start Models
If your generator features remote start — such as the Gentrax GTX4200 Pro or GTX3500 — the onboard battery needs attention during storage. A lead-acid battery left uncharged for months will lose capacity and can sulfate permanently. Connect a trickle charger or smart maintainer every four to six weeks, or disconnect the terminals entirely for extended periods. Clean any corrosion with a wire brush before reconnecting.
Here’s what one of our customers said about the GTX4200 Pro:
“Bought two to run our food truck, for the last 3 yrs has done a lot of hours and never missed a beat. Just top with fuel and oil and can’t go wrong…would highly recommend.”
Choosing the Right Storage Location in Australian Conditions
Dry, Ventilated Spaces
Store your generator in a covered area with reasonable airflow — a garage, shed, or enclosed carport. Avoid spots prone to flooding, direct rain, or prolonged sun exposure, as UV degrades plastic and rubber seals. In tropical and coastal regions, humidity is a persistent concern: silica gel sachets placed near the unit absorb moisture and slow corrosion.
Pest-Proofing Your Generator
Rodents are drawn to wiring insulation and rubber fuel lines in stored generators, particularly in rural sheds. Block the exhaust port and air intake with steel wool or purpose-made caps. Keep the surrounding area clear of food scraps and nesting material.
Use a Breathable Cover
A breathable generator cover keeps dust and moisture off without trapping condensation underneath. Avoid heavy tarps or plastic sheeting, which promote surface corrosion.
Pre-Use Restart Checklist: Getting Your Generator Ready Again
Inspect Fuel, Oil, and Filters
Before starting after storage, remove any rags or caps blocking the exhaust and intake. Check the oil level, refill with fresh petrol if drained, and confirm the air filter and spark plug are clean and secure. If you used a stabiliser, existing fuel should still be usable within its stated shelf life.
Test Power Output With a Light Load
Start the generator and let it idle for three to five minutes. Then connect a small load — a lamp or phone charger — to confirm stable output. For inverter generators, this verifies that the electronics producing clean sine wave power are functioning correctly. Once confirmed, connect higher-draw items like fridges or caravan air conditioning.
Keep Your Generator Ready When You Need It Most
The steps above — treating fuel, changing oil, protecting the unit from pests and moisture, and running a simple restart checklist — take less than an hour and cost next to nothing. In return, you get a machine that starts on the first pull, runs cleanly, and lasts for years.
If you’re looking for a dependable inverter generator backed by genuine after-sales support, explore the Outbax Gentrax range, from the ultra-portable GT800 to the heavy-duty GTX4200 Pro, built for every Australian use case.
