Originally Posted by jimwu
Hi All ! I did open my gear box and check already , nothing wrong inside , shimming all good and the piston compression a bit tight , is it that one cause the problem ?
Piston compression is A-ok, it has absolutely 0 affect on the battery because the spring is what pushes the piston forward to produce compression, not the gears.
You cannot check for shimming by opening up the gearbox that easily. It is something you hear. When you pull the trigger, the gears should make little to no noise when engaging each other. For example: https://www.youtube.com/watch?v=GKRE9ufkAmQ
Things to do:
bevel to pinion shimming method
GOOD lubrication (do not skip this step because it will make shimming moot)
good quality wiring (low resistance, make sure it is not shorting e.g. exposed wires)
Typically a warm battery means there's too much electricity being drawn from the battery due to too much resistance coming from the gears, or some of being redirected such as from a short.
Lubricate your gears well every 2-3 months if not more frequently if you take your airsoft out for shooting a lot.