Probable Root Causes

Large enough wing Efoil dedicated propeller with OK dia and pitch Proven motor size (depends on manufacturer and kV though) Enough voltage (depends on motor kV though)

Some items remain:

• Too high angle of attack for wing (=board angle/nose too high up during starts)
• Too small board (or too high weight)
• Battery that can’t supply enough current
• ESC that can’t supply enough current (assume 100-150A needed for takeoff with 100-120kV motor)
• Poor ESC/motor matching (which ESC?)
• Wrong esc settings (how much current is set for battery and motor? Do you reach full rpm with no load?)
• Wrong remote settings or pairing (do you reach full rpm at full throttle with no load?

I see you have some posts on VESCs, if that’s what you are using then you could check current and rpm during full throttle to see if the system is putting out what it should

--- @Larsb