Hello Liz,
The motor will be hard to come by, the crackling noise you heard suggests to me that it is not the motor but the suppressor, if the noise and smell is coming from the motor try and get to it and there should be something that looks like a fuse or a small square thing near the motor, take it out and discard it, if the smell is coming from the foot control open it up and take the suppressor out and discard it.
drivewithken
October 2010