[Libelle]

In my experience, a m170 spring with a high-torque motor and a 9.6 lipo will not turn over without a mosfet, and it will be notably sluggish even with a mosfet. Also, one could use the stock gears provided they were not crap, but they might need some stress-hardening before placing the spring: that is run the gearbox without a spring for 30-40 minutes first.

 

[Libelle]

You really should get a mosfet if you want to run high voltage. I am not sure how reliable, but my mech says dielectric grease can serve for a mosfet, but you have to keep the grease fresh and happy, or fiz-pop-burn.