How to change movment speed of player

I have a small flying game where you can pick how much power goes into the engines so when there more than 1 power in the engines the player will go faster. I have tried everything a googled a lot to find something else that someone has done and I cannot find anything. How would I go about doing this?

Do you, by any chance, use the CharacterMovement or VehicleMovement components in your Pawn?

Sorry for such a late reply. Im using the character movement component in the character blueprint. I have created a base speed function of 400 and then using the Int for engine power i created and branch saying if == 1 then +200 to character movement but it will never change the speed.

These screenshots are my base speed found in the Character BP and the speed increase code found in the event graph.