A correct servo? Help needed!

[Absurd]

Hi I am still new to the Crawler scene, and I am running a scx - 10 Honcho with 1.9 Tires I have my back up turning servo in which is a Futaba s 3050, Reason why Is because I bought a Futaba S 3305 and the first one I plugged in within a few seconds It started smoking, The second one I used and worked great on a local event all day without a problem a few days later after recharging my 7.4v 2c Battery and plugged it back in It took 20seconds and then started smoking also, I was told IT might be because of it not being lipo compatible. So trying not to waste more money I would like to know what would be the best bet for the problem I have?

Novak brushed motor with Rooster crawling esc the battery is 7.4v 2000mAh 20c Venom, also with a Futaba 3ch Receiver