Model Maintenance Schedule
GasGas EX 300 Maintenance Schedule
The GASGAS EX 300 is a 300cc 2-stroke enduro and cross-country bike. These are the service intervals from the 2026 GASGAS owner's manual in engine hours.
Key Intervals At A Glance
- Oil: Change the gear oil, every 15 hours or every 24 months.
- Air filter: Clean the air filter and air filter box, every 15 hours or every 24 months.
- Top end: Perform minor engine service (change the piston; check the cylinder head; change the O-rings of the manifold and the cylinder head), every 15 hours.
- Fork: Carry out fork service, every 45 hours.
How The GasGas Schedule Works
The GasGas owner's manual lays out service in five columns: after one operating hour, every 15 operating hours, every 45 operating hours, every 90 operating hours and every 24 months. An open circle in the table marks a one-time job and a filled circle marks a repeating one. The manual also warns that harsh conditions such as heavy rain, mud, sand, snow, extreme temperatures or frequent full load can call for shorter intervals, and that intervals can differ by country.
For this model, the gear oil is changed every 15 hours or every 24 months; the minor engine service, which includes a new piston, is every 15 hours; the major engine service, which covers the bottom end, is every 45 hours. Everything else hangs off those service levels.
GasGas EX 300 Service Intervals By Hours
The table below lists the core service items from the maintenance schedule in the Owner's manual 2026 MC 250 / EX 300 (Item no. 3215267en). Task wording follows the manual. Where the manual gives both an hour and a calendar interval, do the work at whichever comes first.
| Service task | Interval | First service |
|---|---|---|
| Change the brake fluid for the front brake. | Every 90 hours or every 24 months | None listed |
| Change the brake fluid for the rear brake. | Every 90 hours or every 24 months | None listed |
| Change the hydraulic clutch fluid. | Every 90 hours or every 24 months | None listed |
| Change the gear oil. | Every 15 hours or every 24 months | After 1 hour |
| Check the swingarm bearing for play. | Every 45 hours | None listed |
| Check the shock absorber linkage. | Every 15 hours | None listed |
| Check the wheel bearing for play. | Every 15 hours | None listed |
| Check the spoke tension. | Every 15 hours | After 1 hour |
| Check the chain, rear sprocket, engine sprocket, and chain guide. | Every 15 hours | After 1 hour |
| Check the chain tension. | Every 15 hours or every 24 months | After 1 hour |
| Change the spark plug and spark plug connector. | Every 15 hours | None listed |
| Change the fuel filter. | Every 90 hours or every 24 months | None listed |
| Clean the air filter and air filter box. | Every 15 hours or every 24 months | None listed |
| Change the damping material on the main silencer. | Every 45 hours | None listed |
| Carry out fork service. | Every 45 hours | None listed |
| Service the shock absorber. | Every 45 hours | None listed |
| Check all screws, nuts, and hose clamps for a tight fit. | Every 15 hours or every 24 months | After 1 hour |
| Check the coolant level. | Every 15 hours | After 1 hour |
| Change the coolant. | Every 24 months | None listed |
| Check the steering head bearing play. | Every 15 hours | After 1 hour |
| Lubricate the steering head bearing. | Every 45 hours or every 24 months | None listed |
| Check the reed valve housing, diaphragm, and intake manifold. | Every 15 hours | None listed |
| Perform minor engine service (change the piston; check the cylinder head; change the O-rings of the manifold and the cylinder head) | Every 15 hours | None listed |
| Perform major engine service including removing and re-installing the engine (change the con- necting rod, big (bottom) end bearing and crankshaft pin; check the transmission and shift mech- anism; change all the engine bearings, the radial shaft seal rings, and the seals) | Every 45 hours | None listed |
The manual is the authority. Check the edition for your exact model year before ordering parts, and shorten intervals for mud, sand, heat or heavy loads.
Fluids And Capacities
| Item | Specification |
|---|---|
| Gear oil quantity (2-stroke transmission) | 0.8 l (0.21 liq. galUS), Engine oil 15W/50, partially synthetic |
| Gear oil specification | SAE 15W/50, JASO T903 MA2, partially synthetic (Motorex Top Speed 4T recommended) |
| Premix ratio / fuel tank (EX 300) | 1:60, Super unleaded 95 octane; EX 300 total fuel tank approx. 9 l (2.4 liq. galUS) |
Ownership Notes
The EX 300 shares its 2026 manual with the MC 250 motocross bike, and the schedule puts the minor engine service, including a new piston, on the 15-hour line, the same as the motocross 2-strokes. That is shorter than many riders expect for an off-road model, so plan top-end parts accordingly.
The manual specifies a 1:60 premix with super unleaded 95 octane fuel.
Track The GasGas EX 300 Schedule Automatically
MotoMind tracks these intervals automatically by engine hours. Add your GasGas EX 300 to the garage, set each task to the interval in the table above, and update hours from your hour meter or the GPS ride tracker. Every task then shows as upcoming, due now or overdue, and your completed service builds a history you can export as a PDF when you sell the bike.
Other GasGas Schedules
Compare with GasGas MC 250F, GasGas MC 125, or browse every model in the maintenance schedules hub.
FAQ
How often should I change the gear oil on a GasGas EX 300?
The 2026 GasGas owner's manual lists “Change the gear oil” every 15 hours or every 24 months, with the first one after 1 hour. Ride in mud, sand or heat, or race hard, and shorten the interval.
When does a GasGas EX 300 need a new piston?
The 2026 GasGas owner's manual lists “Perform minor engine service (change the piston; check the cylinder head; change the O-rings of the manifold and the cylinder head)” every 15 hours. Track engine hours closely so the top end is replaced on schedule rather than after a failure.
How often should I clean the air filter on a GasGas EX 300?
The 2026 GasGas owner's manual lists “Clean the air filter and air filter box” every 15 hours or every 24 months. In dusty or sandy conditions, inspect it after every ride.
How often does the GasGas EX 300 suspension need service?
The 2026 GasGas owner's manual lists “Carry out fork service” every 45 hours.
Can an app track the GasGas EX 300 maintenance schedule for me?
Yes. MotoMind tracks these intervals automatically by engine hours. Enter your GasGas EX 300's hours or log rides with the GPS ride tracker, set the intervals from this table, and MotoMind shows what is upcoming, due or overdue.
Track The GasGas EX 300 By Engine Hours
MotoMind tracks these intervals automatically by engine hours, so your GasGas EX 300 gets oil, filters, top end and suspension service on time.
