What to do when dirt bike gears wont catch?

When dirt bike gears won't catch, first check the clutch lever for proper adjustment and ensure it's not overly tight or loose. Inspect the clutch fluid levels and bleed the system if necessary, as air in the lines can cause issues. Additionally, examine the shift linkage for any obstructions or damage, and ensure that the gear oil is at the correct level and not contaminated. If the problem persists, a professional mechanic may need to inspect the internal components of the transmission.