8mm bronzey bushings usually on 99% of them
(FireHawk has 8mm bearings for some reason)
These softer bronzey bushins do wear so replace with shs bushings over time
Gear ratios are "usually" 18:1 - though oddly FireHawk seems to be 21:1
most gearboxes use 18:1 as stock std gears - a few makes may use 16:1 but reckon 85% use 18:1
(some other types like L85's M14's may use 21:1 gears in longer stroke gearboxes but 18:1 is the "norm")
Piston is a 16 tooth type - well sometimes referred as a 15 tooth if 2nd tooth is removed/missing for AoE
But it is still a 16 tooth piston really coz sector gear has 16 teeth on std aeg gearbox
Think the cylinder spec is about 72mm x 23.8mm internal diameter - yup think that is about it I guess
screws to open G&G v2's are located on opposite side to a std non blowback box
don't know why but G&G put screws underneath on regular v2's - though think blowback's are on top
screws 90% will be allen key types - but some are still the odd phillips screws
Upgrades......
double o-ring cylinder head
o-ring nozzle
new piston head - better plastic one
cylinder - usually fine unless port is incorrect
Correct AoE, sorbo/neoprene pad
check seals etc......
grease blah blah blah
you have a mosfet fitted anyway - can't say how robust it all is but a fet is there all the same so donkey work is done
TBH - leave it as it is for now - you have a fet so you could run on higher juice for a while
Then eventually when it NEEDS to, either it needs a service or she wears a bit or something busts..
THEN - re-do the box with tweaks/service/repair etc.........
That is my best advice - if it ain't broke.... etc.....
Even if you buy another "enhanced" or "upgraded" box it will still most likely need a tweak here n there
Quick change spring boxes are nice but on M4's you still gotta remove most stuff to change spring
just you haven't got to open box - but still gotta do 90% or removal to get to rear of box
(unless you wanna drill out a big dirty hole at back of receiver and need a stock change/adapter)
yes on some other guns (APS UAR) the quick change spring works great and 30 sec spring change but not on M4's
on a tweaked box you are gonna be looking at £100 aprox for a mofo lonex box
a £40/£50 gearbox will be nigh on just a std box and G&G boxes are pretty nice to work on with good compatibility
Leave it as is for now, run a bit more juice maybe
then say 6 months or so then get her tweaked and serviced a bit, drop in a neo motor and she will be lovely
BTW not saying run on 11.1v with a high speed neo motor trying to hit 30rps - that is silly
doing that will lead to piston pickup tooth snapping off - coz did that twice at first
but a little more juice or maybe a motor on 7.4v getting up near 20rps should be ok for a little while
probably replace small tamiya connectors with deans is cheap easy tweak