Pull the cover; if the filter is filthy, the owner likely neglected critical maintenance.
Scan for weeping around fork seals, the rear shock shaft, and engine case gaskets. Key Tips for Buying a Used Dirt Bike Checklist buying a used dirt bike checklist
Check for "milky" oil (water contamination) and ensure the coolant is full and clean. Pull the cover; if the filter is filthy,
Before starting the engine, check the bike's physical condition and signs of maintenance: Pull the cover