From FCOM
ENGINE START switch ................................................GRD F/O
Verify that the N2 RPM increases. C, F/O
When N1 rotation is seen and N2 is at 25%, or (if 25% N2 is not possible), at maximum motoring and a minimum of 20% N2:
Note: Maximum motoring occurs when N2 acceleration is less than 1% in approximately 5 seconds.
My question is moving the engine start lever to IDLE detent preferred once the N2 25% or you wait maximum motoring as I see some captains wait till it reach 29 to 32% and they said this to avoid hot start problems.
also what is the exact definition to the term "Maximum motoring" as I want you to correct my understanding to the above paragraph as I believe it means not more than 25% [[
(if 25% N2 is not possible), at maximum motoring]] this why I wonder why captains wait till the reach higher N2 i.e: 29-32% ?