M89 nozzle

[chillfire]

Hi all, 

A newbie here, apologies up front for lack of knowledge on all of this.

I bought my son a Double Eagle M89 second hand while at our first event a few months back and it was brilliant.
The guy said he had upgraded the motor and it was coming in at around 270 FPS.
However it started to misfire on the 2nd outing and the hop up slide panel got stuck open.... I started to smell a lemon.

After comparing all the internals to some youtube videos, it looked in pretty good nick, but I noticed the nozzle wasnt made from nylon or aluminium and appears to be 3d printed and it has a crack in it caused by my idiot fingers trying to dismantle everything.... wally I know
I am assuming that the issue was with the nozzle, or at least it is now, but have absolutely no idea how long the nozzle should be for the rifle should be.
Looking online and speaking to a couple of airsoft shops, I cant find any docs to say what size it should be...

Does anyone have one they can measure, or know the size it should be?