Okay. If the starter and flywheel are good then the sound you are hearing is due to the engine trying to fire (trying to run on it's own).
Stated differently, the engine is overcoming the speed of the starter.
Does that make sense with what your are hearing?


"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."