Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Here is the beep code chart, and it shows you have armature open, check connections at the motor and then the motor! Sputtering could have been the motor brushes arching on the armature.
Check the connections at the motor, and there is a way to run a test on the motor. Here is link to the motor test, you will have to scroll down the opening page past the manuals to find the troubleshooting guide wih motor test.
I see question is till open, did you run the motor test?