Storing and Winterising Your Dirt Bike Over the Off-Season
A bike that sits unused for months develops its own problems if you don't prep it first. A bit of care now saves a messy, expensive restart later.
Fuel is the first thing to sort
Old fuel left sitting degrades and can gum up carburettors and injectors over a few months, causing hard starting or rough running later. Either run the tank close to empty before storage, or fill it completely and add a fuel stabiliser — a nearly-empty tank with lots of air space actually encourages condensation and rust inside a steel tank, so full-plus-stabiliser is usually the safer option.
Change the oil before storage, not after
Used oil holds contaminants and acids that can sit against internal engine surfaces for months if left in over winter. A fresh oil change right before storage protects the engine far better than doing it when you pull the bike back out.
Battery care
A battery left connected and unused will slowly drain and can be damaged by deep discharge over a long winter. Disconnect it, or better, put it on a smart trickle charger designed for motorcycle batteries, which maintains charge without overcharging.
Tyres and suspension
Where possible, get the wheels off the ground (a stand or similar) to stop tyres developing flat spots from sitting under constant load in one position. If that's not possible, at least move the bike occasionally over winter to shift the contact patch.
Keep moisture and pests out
Plug the exhaust and air intake with a clean rag (and remember to remove it before next starting) to stop moisture, insects or rodents getting in. Store under cover if you can — even a basic cover in a garage or shed makes a real difference to corrosion over a wet NZ winter.
A simple pre-storage checklist
- Fresh oil and filter
- Fuel stabilised or tank drained
- Battery disconnected or on a trickle charger
- Chain cleaned and lubed (it still rusts sitting still)
- Bike covered, ideally off the ground
Thinking about selling instead?
If the bike's not getting ridden enough to be worth storing, it might be worth more to you as cash towards something you'll actually use. See Sell Us Your Bike for a no-obligation value, or browse our current stock if you're after something different for next season.
Frequently asked questions
Should I drain the fuel before storing a dirt bike?
Either run the tank close to empty or fill it completely and add a fuel stabiliser — a mostly-empty tank can actually encourage condensation and rust, so full-plus-stabiliser is usually safer.
Should I change the oil before or after winter storage?
Before. Used oil holds contaminants that sit against engine surfaces over months of storage, so a fresh change right before storing protects the engine better.
Will a dirt bike battery die over winter if left connected?
It can — a battery left connected and unused slowly drains and deep discharge can damage it. Disconnecting it or using a trickle charger is the safer option.
How long can a dirt bike sit without being ridden?
With proper storage prep — fuel stabilised, fresh oil, battery maintained — a dirt bike can sit for several months over winter without major issues.