Just remove it from the car and clean it. Open it up and check if the piston/liner is worn out.
If the piston can be pushed above the top of the liner it is most likely worn out.

People on the board doesn't have X-Ray vision so you do need to put some effort in.

Besides do the normal maintenance routine:
- Use clean airfilters
- Check fuel and pressure lines for leaks
- Check fuel filter and clean it if needed.
- Check servo linkage, does it open the carb 100% ?
- Check clutch shoes and springs on a regular basis.
- Clean the car at least every other day of running. I know fail doing this frm time to time.