Ultimate (ASG) M4 Gearbox fire Selector Problem

[obious]

Hi All,

In an effort to keep this short, I bought a new Ultimate (ASG) M4 to go into my G&P M4. After installing it, I checked the function of the fire selector and noticed a problem.

When in 'Safe', it was possible to still pull the trigger. After inspection, it appeared as though the 'safe' position detent of the fire selector (on the internal side of the lower receiver) was pushing the trigger plate too far and causing the gearbox to nullify the selection of the 'safety' position. With that in mind I removed, by filling, a small portion of the selector disc that sides inside the lower receiver but after reassembly, it appears as though now my M4 won't fire in full auto mode. Possibly due to the selector plate of the gearbox not being pushed properly into the 'full-auto' position.

Does anybody know how to fix this?

Thanks!