the savage .25 motor is suppose to be almost identicle, i know for a fact that my roto start backplate on my xtm 24.7 will fit the savage .15, and i have compared the 2 and they look just alike, you should check out that motor because it has more power than the xtm 24.7, my buddies savage will beat my x factor in acceleration and top end and he has the .21 savage