Carl Mark Cooke output shaft diameter is 3.00mm

Carl Mark Cooke yes. the unit is compatible with pretty much any standard 3pin receiver plug

Carl Mark Cooke couldn't tell you what the rpm is, as it would depend on the battery esc combination you were using. I can say that this is the fastest upgrade for the heng long tank as A direct replacement, recommended you use the 6.0 or higher controller. it has made a massive difference in speed in my Heng Long Challenger II and Leopard 2a6 tanks

Carl Mark Cooke if the MN98 is the landrover bodied model, then the shaft will fit. not sure about the mn86, though, as that uses a larger motor and different axles

Carl Mark Cooke If you use this, you will need to fit a hobby grade receiver and transmitter, and a 3 wire servo . you can still use the original fit lights, but you will need to wire in a 220 ohm resistor and fit the lights with a suitable plug to fit the receiver

Carl Mark Cooke this will not work with the original wpl transmitter. also note that main power is wired the opposite way round on an mn board, be careful when connecting to other batteries

Carl Mark Cooke No. you would need to use aftermarket radio to use this esc. I recommend flysky gt3c, this esc and 17g servo of your choice

Carl Mark Cooke yes, it has metal gears and is ballraced on the transfer gear and lower output shaft