Old Skool Brushed motor modifiying

[Miggers]

Yeah ,I know all you fancy dan speed merchants use brushless these
days,but I've a few questions about good old brushed motors.

I have a spare 27turn stock motor that hasn't got a load of miles on the clock.
The brushes and comm are in pretty good nick,so I'm wondering about
having a tinker with it.

If I take enough wire off the windings to bring it down from 27 to 19 turns
would it still run?

Or do I have to get completely new wire of a different gauge and completely rewind it?

Miggs