M16 Only Shoots Full Auto

[mood]

As above, my m16 is only shooting full auto, even when in the semi position with the fire selector. The cam does seem to be engaging with the fire selector plate and moving it between safe semi and full.

Is there something inside the gearbox that could cause semi not to work?

[Tom Andrews]

Re: M16 Only Shoots Full Auto

Either the tiny spring between the selector plate and the semi/auto cam on the outside of the gearbox has gone missing or the cam itself inside the gearbox has worn or is broken.

[mood]

Re: M16 Only Shoots Full Auto

Hi Tom, thanks for the response. I think the spring your referring to is there. In the middle at the top of the fire selector plate? will try taking it apart to look for the cam inside. Don't suppose anyone could point me in the direction of what the cam looks like? Maybe using the pics in the thread pinned at the top of the tech-electric guns as a reference?

[Tom Andrews]

Re: M16 Only Shoots Full Auto

The cam part is inside the gearbox, and bears against a lobe on the gear that pulls back the piston. You would need to remove the gears and possibly the trigger assembly, this is because as the cam arm moves up and down it lifts the trigger block to reset single shot.
Sometimes the part of the arm that lifts the trigger block snaps off.

[dave38x]

Re: M16 Only Shoots Full Auto

Could be the part on the switchblock that engages the cutoff lever is worn as well!

[mood]

Re: M16 Only Shoots Full Auto

Cheers tom i will take it apart and have a look.

dave, is that the switch on the outside of the gearbox? or part of the trigger on the inside of the gearbox?

[Tom Andrews]

Re: M16 Only Shoots Full Auto

As Dave rightly says, the trigger block itself could be worn, the cut off lever (Why couldn't I remember what it was called last night?) lifts the rear of the block for semi. All the switch parts and trigger are inside the gearbox.

[mood]

Re: M16 Only Shoots Full Auto

Cheers guys will take it apart and have a look