The fuel cap can be taken apart for inspection and cleaning of the tank vent.
1
Use a screwdriver and prise off the housing (A) that contains the non-return valve (B) and cover (C).
2
Blow the filter (D) and the hole in the fuel cap (E) clean with compressed air.
3
Assemble the fuel cap in reverse order to that in which it was dismantled. Make sure the seal (F) is not damaged.
⚠️NOTE:There is a small slit (G) in the nonreturn valve (B) that only becomes visible when you carefully squeeze its sides. If the valve is undamaged, the slit is not visible in its normal position. Replace the non-return valve if necessary.