Gearing help for a mt4 g3 truck ?

[speedy]

Hi !

I need some help on how to gear my mt4 g3 mt properly
now i run a 14/50t setup on 4s but the damn front Wheels won't stay on the ground so i have no steering controll and the topspeed is low
The motor i an 4-pole 2000kv 40x75mm inrunner.
After maby 25-30min of runtime in grass and dirt he motor is warmer than the esc and lipopack (5000mah 50c 4s) isen't there a rule that if the motor is hotter than the esc then its undergeared ?

I can hear that the motor reatches max rpm almonst a soon as i tutch the throttle and then the front's in the air.

chould i gear up to 16/50 or change diffoil ? i haven't changed any oil in the diffs so there is the stoch oil in them !

i was thinking of this setup R 100 000k C 300 000 F 500 000k ?