Double Eagle UMP

Head_Hunter

My DE UMP has been double shooting in semi-auto mode since the day I bought it. Sometimes it shoots anything up to 6 bbs at a time.
I've tried two different DE mags and the problem still persists, so I doubt its a mag feed problem. Full auto mode is perfect by the way. I've brought the gun back to the retailer many times, but he could never re-create the issue in store. I have tried to video the double shooting, to prove I am not messing, but it's impossible to capture the bbs in flight with the standard camera I have.
I disassembled the gearbox (version 3) last weekend and could not see anything wrong, except that the grease was dirty. After re-assembling the gearbox the rof was slightly better, due to new grease and general parts clean. The gun still double shoots however.
Has anyone ever heard of this issue before? Any suggestions on how to fix it?

Stercus Accidit

Is your hop up turned on at all?

And is the air nozzle correctly attached to the tappet plate.

Usually double feeds are caused by the hop being off, or the hop rubber being badly installed.

ED E

Is the gun actualy firing twice or once with 2 bbs? The selector in the DE UMP is a little finiky, its the only con. Your safety may start self releasing while the selector is still in safe.

If its a single shot with multiple bbs then may I ask this, tip the barrel down, fire a few shots, see if any roll out. I had problems before with it "multi-loading". Just reassembled the hop and that was that.

Head_Hunter

Motosam wrote: »

Is your hop up turned on at all?

And is the air nozzle correctly attached to the tappet plate.

Usually double feeds are caused by the hop being off, or the hop rubber being badly installed.

Yes the hop up is on and it works perfectly, its the only thing that is perfect. The air nozzle is attached to the tappet plate properly, but is slightly loose.
I have installed many hop ups and never had any problems, the UMP hop up has been installed 4 times and changed twice, it is perfect.

Lethal_Bullet wrote: »

Is the gun actualy firing twice or once with 2 bbs? The selector in the DE UMP is a little finiky, its the only con. Your safety may start self releasing while the selector is still in safe.

If its a single shot with multiple bbs then may I ask this, tip the barrel down, fire a few shots, see if any roll out. I had problems before with it "multi-loading". Just reassembled the hop and that was that. .

It fires once with 2 or more bbs coming out at a greatly reduced power level. I will try firing the ump at the ground later so. by re-assembling the hop, do you mean taking the whole unit apart or just re seating the bucking?

ED E

Head_Hunter wrote: »

Yes the hop up is on and it works perfectly, its the only thing that is perfect. The air nozzle is attached to the tappet plate properly, but is slightly loose.
I have installed many hop ups and never had any problems, the UMP hop up has been installed 4 times and changed twice, it is perfect.



It fires once with 2 or more bbs coming out at a greatly reduced power level. I will try firing the ump at the ground later so. by re-assembling the hop, do you mean taking the whole unit apart or just re seating the bucking?

Well, they're one step apart. I'd suggest 1, check the little ring yoke(whats the real name richie?) between the arm and bucking is still in place. If it wasnt the bbs would easily pass. 2, Get a guarder 120% bucking and see if that sorts it.

Head_Hunter

Lethal_Bullet wrote: »

Well, they're one step apart. I'd suggest 1, check the little ring yoke(whats the real name richie?) between the arm and bucking is still in place. If it wasnt the bbs would easily pass. 2, Get a guarder 120% bucking and see if that sorts it.

I have a guarder bucking installed, have you a picture of this "ring yoke"?

ED E

Head_Hunter wrote: »

I have a guarder bucking installed, have you a picture of this "ring yoke"?

You know it man, the piece of rubber between the hop unit arm and the bucking itself, you get one in the pack with a bucking too.

Eh, as below:

Head_Hunter

the nub?

ED E

Head_Hunter wrote: »

the nub?

Yeah:P

Head_Hunter

lol, I took a look at the hop up unit and the nub is in place. I understand where you're coming from, if the hop up rubber is not protruding enough the bbs will roll down the barrel when you aim it down. I had that problem with my M9 at first, until I found the very well hidden hop-up adjustment nut:D. All is fine with the hop up.

ED E

Do you use silicone?

Head_Hunter

Silicone spray on the magazine once, when I first got the gun. I don't put silicone oil near the hop-up.

ED E

Head_Hunter wrote: »

Silicone spray on the magazine once, when I first got the gun. I don't put silicone oil near the hop-up.

Could still be some on the rubber/on the mag.

Turn it fully off, use a cleaning rod, turn it back on and test it again. It has to be hop related if the air nozzle is in the correct position.

Head_Hunter

I will give that a try, thanks for all your help. If cleaning the mag and hop-up does not work, I will re-check the air nozzle, maybe even tighten its fit with some PTFE tape.

ED E

Head_Hunter wrote: »

I will give that a try, thanks for all your help. If cleaning the mag and hop-up does not work, I will re-check the air nozzle, maybe even tighten its fit with some PTFE tape.

The only thing that will do is increase FPS. It just makes a batter seal.

Head_Hunter

So the only thing that would cause the double feed is silicone oil on the hop and mag lips?

ED E

Basically, bbs are pushed up, hop holds them when the nozzle pushes foward, then air fires them. Either the hop isnt holding them on there is an issue with the nozzle. I know I've put one on behind rather than in the tappet plate, not very noticeable while assembling but a crucial mistake. Just make sure. Second, try different bbs.

Head_Hunter

Will do, thanks.