BB's are a no go.....

[VooDooPeteK]

OK so I had some electrical issues in my M4.

Tore the gun down since I had it all apart i figured I would add some upgrades I had in the tool box.

So fixed the electrical problem, added new spring, air seal nozzle, TBB and hop up bucking.

mechbox sounded good so I put the gun back together but when I went to go test fire the gun today it wont spit out any Bb's. They load into the hop up but then that's it.

what should I be looking at now to remedy this problem?

Thanks

[coach]

did you turn the hopup completely off when test firing? is the bucking installed correctly? does the rubber sit evenly when you look at the back of the hopup unit?

[HKGhost]

Sounds like your bucking. Take that out and take a look. Also check by putting a bb down into it and see what kind of force takes to push it. It shouldn't be hard to push.

[13Fido13]

Make sure the rubber sleeve for your hopup isn't severely out of round. Make sure you can see your bucking adjusting inside the barrel when you adjust it.

[Dohpaz]

Had the same problem on my G&G M4 when Aegiis was changing the spring in it.

No BB's were coming out at all when shooting.

It was the tappet plate spring that wasn't placed. So the Piston wouldn't rock back and forth it would just stay there even though the spring was working fine.

Hooked the spring back up, plugged the battery on the mechbox and test fired and it was now going back and forth. Put everything back and voila!

[Con Murder]

[QUOTE=Dohpaz;1239877]
It was the tappet plate spring that wasn't placed. So the Piston wouldn't rock back and forth it would just stay there even though the spring was working fine.
QUOTE]

I'm sure the piston was fine if it was the tappet spring like you say...

Anyway, OP I have an m4 I am helping a friend fix up that has the same problem from a simple barrel swap. We find it shoots about a hicap before it stops ejecting the bbs. This is due to some movement between the ho-up unit and the mechbox, we can push them back together while it is assembeled (through the dust cover) and 'fix' the air leak for a couple dozen rounds but then its beat again. It seems the outer diameter of the new barrel allows some play and so now the entire hop-unit is no longer tight. To fix this I am going to place an o-ring around the barrel/ hop-unit to keep the unit from having any extra room. If yours exhibits the same symptoms feel free to pm me for a follow up, its going down this weekend.

[Gunny_McSmith]

Originally Posted by Con Murder

I'm sure the piston was fine if it was the tappet spring like you say...

Anyway, OP I have an m4 I am helping a friend fix up that has the same problem from a simple barrel swap. We find it shoots about a hicap before it stops ejecting the bbs. This is due to some movement between the ho-up unit and the mechbox, we can push them back together while it is assembeled (through the dust cover) and 'fix' the air leak for a couple dozen rounds but then its beat again. It seems the outer diameter of the new barrel allows some play and so now the entire hop-unit is no longer tight. To fix this I am going to place an o-ring around the barrel/ hop-unit to keep the unit from having any extra room. If yours exhibits the same symptoms feel free to pm me for a follow up, its going down this weekend.

did you forget to put the spring that goes in front of the hopup unit? (see pic)

[VooDooPeteK]

Originally Posted by Gunny_McSmith

did you forget to put the spring that goes in front of the hopup unit? (see pic)

Nope no spring on mine when I looked again and don't remember it having one so time to look around the work bench fo rit lol

also what is that small piece in from of the bucking in that picture? and where does it go?

[Gunny_McSmith]

Originally Posted by VooDooPeteK

Nope no spring on mine when I looked again and don't remember it having one so time to look around the work bench fo rit lol

also what is that small piece in from of the bucking in that picture? and where does it go?

thats hopup bucking nub.... (see pic)



that's the part that pushes the rubber down,

The small spring pushes the hopup unit backward, for a better airseal, and also acts like a bumper, each time the piston slams forward (energy transfer...wont get into deep physic explanations here...), reducing wear on your upper receiver, and on the hopup unit itself....

[VooDooPeteK]

yea I never took apart the hop up just left the old nub in and changed the bucking.

Now I have to look around for a spring that will work on the front of the hop up

[Gunny_McSmith]

mechanic pen spring? ...might fit.. I'm not sure...