M4 firing low on Chrono... Help

[Qlimax]

Hi,

Need some advise, I've upgraded my M4 gearbox and now it's firing extremely low on Chrono. I've done all the usual checks but now I am at a loss. ive checked the compression it's solid, checked the wiring perfect, it isn't the spring or piston as they are brand new.

at the moment on a Lonex M100 spring it only firing at 180Fps should be more around 330Fps.

HELP.

 

[Alex The Destroyer]

Could be the air seal.

EDIT: Disregard above comment, just learnt that compression and an air seal are the samer thing.

 

[Rock-climby-Dave]

Is the timing on the air nozzle right?

Does the piston fire when the nozzle is fully forward, or is it coming back before the piston fires?

 

[sp00n]

what upgrade did you actually do to the gear box?

 

[Qlimax]

Spring,piston,piston head, gears and full trigger loom replacement.

I've found it's one of two things, either the Hop-up seal or the rubber round the cylinder head. Eveything is firing as it should be just very low on chrono.

Have a few ideas so will try them and post back the results.