Yuukan

Gate don't recommend brushless motors with their mosfets/FCU's. Some reports of damage being caused to either or both components (possibly caused by active braking, but unclear). The brushless motors don't have a mosfet exactly but they do have an electronic control unit to make the motor work.
 
I'm suggesting that, given that position and that the Marui is impossible to get spares for right now, is it worth risking buggering it up? The stock motor's an EG1000, so you should be able to pull anything you need to for UK limits without any problem.
 
Might be fine of course. But, given the cost of the gun and the motor...

I'd be lying if i said I knew as I can't remember for the life of me. Any GBB mount should fit if thats any help.

Perfect example of people's stupidity.
Fancy useless aftermarket hop chamber but kept the shit stock cylinder.
 
The rough bolt pull happens because of the AS01 45° sear and the utter shit brass cylinder. One small free thing you can do is to get rid of the cocking indicator. More useless than that fancy AA hop chamber your mate spend way too much on, it grinds against the cylinder side and, to be fair, nobody cares about a visual indicator that your cock is gunned.