M4 Issue, BB's only going about 2fps lol

[Sacre]

So I went to fire my gun earlier, and sure enough, (after a full battery charge) when i fire the BB's shoot about 1 foot before hitting the ground, and some just roll out.

I took apart the gun (but not the gearbox) and checked the barrel/hopup unit. Thats fine, but it seems the mechbox isn't pumping out as much air as it used too, it still fires around 22rpm, but the air being put out is minimal.

Am i going to have to open the gearbox on this? really don't want too lol.

So the basic issue (from what i've seen) is that the air being pumped out is minimal, after a full charge.

PS, tried to post this in the doctors corner, wouldn't let me. Not sure what I missed there.

Thank you.

Edit - Or, the air is escaping another way

[Caboose03]

my old Jing GOng M4 was doing that to and it turn out the the tappit plate and the sir nossel came apart . all i had to to was put them back together and it fired fine. also check ur O-ring on the pisson head for any cracks breaks or scraches, that will also lower ur compresion. that all i can think of right now Ill post more if i think of anything else

[marcwhite]

I believe what caboose said is true, it sounds like its the tappet plate.

[Sacre]

Turns out the O-ring on my Piston is snapped.. rolled off
You know that little hole on the side of the gearbox? all the air is escaping out of there.

So whenever i can, going to grab an oring from a homehardware that will fit snug, some grease, and grease her up good. That'll probably fix it

Originally Posted by Caboose03

my old Jing GOng M4 was doing that to and it turn out the the tappit plate and the sir nossel came apart . all i had to to was put them back together and it fired fine. also check ur O-ring on the pisson head for any cracks breaks or scraches, that will also lower ur compresion. that all i can think of right now Ill post more if i think of anything else

[Caboose03]

at princess auto u can get a 150 piece O-ring kits for like $15