Chuck this is awful, and it makes me hopping mad!! No flywheels? The worms are probably pressed onto the motor shafts, so upgrading the motors to something better would be a big job. Exact replacement motors could be fitted if the parts are available. But they would probably burn out just as quickly. Lionel should be ashamed of itself for selling such an under-engineered and under-spec'd loco! It's a marketing failure too, because if someone's first experience is frustration and disappointment, there won't be a second purchase! 
I feel so badly for the young boy... I'm willing to personally wire you a cash contribution to buy him something better, with real, built-in quality they way they USED to be made! Maybe you can find out what his favorite railroad is, what radius of curve, which transformer, etc. Life is too short to drink bad wine. And thou shalt not suffer a witch to live!
