nothing but temps?

ok here is my gearing (the lhs was out of 38 tooth spur gears and i have the 40tooth) and it is geared for 40 but my motor is getting hot and nothing else its the narrow gear set. do i need to gear up to bring temps down?

Differential Ratio: 2.8461538461538463
Transmission Ratio: 2.5
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 18
Total Voltage: 18.5
Motor KV: 2000
Tire Diameter (inches): 5.75
Tire Ballooning (inches): .2
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.22 : 1
Total Ratio: 15.81197 : 1
Tire Circumference (inches): 19.32 inches (490.75 mm)
Total Motor Speed: 37000 RPM
Vehicle Speed: 42.81 mph (68.77 km/h)
Estimated Adjusted Speed: 40 mph (65 km/h) - 6% loss
Effective KV Value: 2000
KT constant: 0.68 oz-in/A