Segway FUGLEMAN SGW1000F-U2 Owner's Manual page 129

Spark plug is located under the cargo box. Refer to page 103
how to open the cargo box. When replacing the spark plugs, replace
both spark plugs at the same time.
1. Remove the ignition coil fixing bolts.
2. Take out the ignition coil. Spark plug is located below the
ignition coil.
3. Using the spark plug wrench provided in the tool kit, remove
the plugs by rotating them counterclockwise.
4. Reverse the procedure for spark plug installation. Torque to
specification.
Normal spark plug: the insulator is grayish-white, grayish-yellow
or light-brown, and the electrode gap is about 0.7-0.9 mm.
If the spark plug shows electrode wear, carbon deposits or gap is
too large, replace the spark plugs.
MAINTENANCE AND STORAGE
117