Rocket

Best guess given the limited information is the starter wiring is to small. I have seen this in other Massimo models. Try replacing with #8 wire. To test If this will help,

use a fully charged car battery and jump with good quality cables directly to the starter motor terminal. Also, use a good ground next to the starter. Could also be a bad starter or other issues.

Starter motor Massimo T Boss 410 UTV.  The starter motor will sometimes stall at compression stroke. Battery wires are to small to carry the amperage the starter motor requires. When the motor stalls it uses a lot of power and heats up. It will burn out the windings in the motor. Massimo part number for the starter is 24101. 

Please outline all the trouble shooting you have done so far. Things like, does the spark plug spark. Does the coil get 12 volts? and so on. Stuff like that would be a big help in getting help.

Put a "FARM USE" tag on mine.  That covers it all and no taxes.

T-Boss 410 side by side supper loud backup beeper alarm is located on the passenger side behind the battery. Just unplug it and maybe use that circuit for back up lights. Best access in through the shifter panel on the dash. Remove the shift knob and the three screws on the panel.  Reach in there and unplug the beeper.

Here is the dirt on the Massimo T boss 410 UTV side by side differential. It doesn't have one in either the front or rear. It’s simply a ring and pinon gear set. Therefor it can not be unlocked. It’s always, permanently locked! I asked Massimo if there is a locking differential option for this model, NO. Is there an after market locking differential available for the 410 side by side? So far google has not found one.