Yes@K155Y a few things to try...
1) Fresh battery?
2) lube (what are you using)?
3) are the can and bolt head tightened?
4) is the back cap screw tightened down?
5) Lastly what air regulator are you using? The ASA pin may not work too well on the Ninja Pro V2 regulator so it may be starving the marker. Blast can ship you a new pin if this is the case.
Is the Ninja reg the one with the ball bearing or the pin??Yes
Dow 33
Yes
Yes
Ninja slp
I have tested my engine in ur old gun with g4z and it shoots fine also the shrayder valve is fine I think it is the solenoid because when you shoot the gun it pukes air out of the little hole at the back of the gunIs the Ninja reg the one with the ball bearing or the pin??
Have you taken the HPR off and tested the Schrader Valve?? **All you need to do is unscrew the HPR and turn the air on (DONT SHOOT IT) just see if the schrader is leaking.**
Failing all of these things...see if you can find someone with an insight; swap engines and test.
Hope you get it sorted