Honda WT20X Owner's Manual page 31

5. Spark arrester maintenance (applicable types)
The muffler becomes very hot during operation and remains hot for a
while after stopping the engine. Be careful not to touch the muffler
while it is hot. Allow it to cool before proceeding.
The spark arrester must be serviced every 100 hours to maintain its
efficiency.
WT30X·WT40X
1. Remove the six 5 mm screws from the muffler protector, and
remove the muffler protector.
2. Remove the 4 mm screw from the spark arrester, and remove the
spark arrester from the muffler.
MUFFLER PROTECTOR
5 mm SCREWS
MUFFLER
30
SPARK ARRESTER
5 mm SCREWS
4 mm SCREW
SPARK ARRESTER
4 mm SCREWS
[WT40X Type only]