You Do Need power plug adapter while traveling from Guinea to East Timor (Timor-Leste).

Here is Why You Need An Adapter

The outlet and plug type used in East Timor (Timor-Leste) are C, E, F and I and in Guinea are C, F and K. This is how they look like.

Guinea

In Guinea, outlets of type C, F and K are in use.

Type C

Type F

Type K

East Timor (Timor-Leste)

In East Timor (Timor-Leste), outlets of type C, E, F and I are in use.

Type C

Type E

Type F

Type I