Replace metal gears in the gearbox.
Upgrade to 370 motor.
Stock Gearbox replace metal gears.
Look for 370 motor with long shaft or atleast 13mm long.
The conversion kit or spacer comes with motor pinion.
Still all are stock.
Product Link:
MN82 Metal Gears and Motor Converter Spacer
https://shope.ee/qKBKvzLeS
370 Motor Long Shaft
https://shope.ee/8f32fcK3xB
(Sold Out)
New Link
370 Motor Long Shaft 21000 RPM
https://s.shopee.ph/5pmpMBu7KV