I bought a 6 year old, very slightly used e revo from a friend. MMM system. Both the ESC and motor are brand new via replacement from Castle. With brand new 3s lipos and 18/54 gearing I'm struggling to hit 45 mph. Did the torque test with castle and the kv on the motor is fine. No transmission issues as there's plenty of torque and without the pinion engaged it rolls smooth.
Is it possible that it is in training mode?
Running forward in reverse? Calibrate esc to radio?
To hit 65 mph you need to gear it 21 / 54 ...
What kind of tires are on it ? What kind of surface did you ran it on ? There are a lot of variants ...
better than that..... try 28/50.... smiles
yeah, it sounds like the esc isn't calibrated correctly or the motor isn't wired correctly or both. make sure the motor wires go A to A and B to B and C to C. otherwise it will run sluggish.
"It's just RC, not rocket appliances"-Ricky