Semi fires full auto

[wKnight]

I just finished upgrading my gun and everything works fine except semi-auto fires full auto. Full auto still works normally. any suggestions?

[Goldman]

Brand? Model? Upgrades/changes? key things we need to know.

[Tankdude]

TM M4 RIS.
Has the 007 upgrade package.
Reinforced Mech, Gears, AL piston, bushings. PDI 170%.

[CDN_Stalker]

Have heard this happen. When you put the mechbox in the lower receiver, did you have the selector switch set on semi? If not, it'll fire full all the time. Could also be the little doo dad (connects to the selector plate spring) inside the mechbox that interrupts the sector gear to make it fire semi isn't aligned properly.

[wKnight]

how does one make sure the doo dad is alligned properly?

[Sgt.Hartman]

hi what make that problem can be:
1- the little spring on the selector plate
2- inside the gearbox, behind the electric assembly for trigger, there is a little moving part, like a rocker. Be sure you didnt forget to put it and it is easy to move, this is what make the gun stop after one shot, the cam on the gear make it move and move the contact pilot to get back to its place and stop the contact. its like a rocker on a fuel motor.

if it was working before, it can only be those 2 possibility.
good luck

[Tankdude]

Originally Posted by Sgt.Hartman

hi what make that problem can be:
1- the little spring on the selector plate
2- inside the gearbox, behind the electric assembly for trigger, there is a little moving part, like a rocker. Be sure you didnt forget to put it and it is easy to move, this is what make the gun stop after one shot, the cam on the gear make it move and move the contact pilot to get back to its place and stop the contact. its like a rocker on a fuel motor.

ok, I have the gun with me now. I spent 3 hours on it last night at a game using glow sticks as my lighting.

The spring is there, the rocker is there. It is not that simple

After giving myself a crash course in semi function in v2 mechboxes I now know how they work and everything.

The rocker is not lifting the connecter high enuf to release it from the trigger.

I think the cam on the gear is too short/small. The spring that pulls back the connector looks fine. The rocker is seated nicely and is in the groove.

The rocker just doesn't want to lift the connecter.

Solution1: File the connecter down so the rocker does have to lift it as far?
Solution2: problem with the gear itself, convert back to stock.
Solution3: Add some mass/stuff to the rocker so it moves more.

The problem seems to be too much pressure on the connecter and not enuf force being applied to the rocker.

Solution4: The reinforced mech box: the peg on which the rocker sits is not place correctly or is not big enuf to hold the rocker in place firmly enuf. This was my first impression, but I don't see a mechbox defect being the case. This is just my engineering brain kicking in.

[CDN_Stalker]

I'd be curious if the problem persists if you changed back to the stock gears. Hey, would be a useful peice of info, and all part of troubleshooting. Try one thing at a time to narrow the problem down.

[Tankdude]

Fixed it. Solution 1

Took my knife and slighty rounded down the connecter. Very slighty. Added some WD40/sunflower oil and replaced the PDI 170% with PDI 130%. Also reheated the spring (connecter retracter) and cooled it in oil to reshape it some so it would help the rocker some.

I replaced the spring because I have too many lumps on my head from this gun. I'll switch it back to the 170% after a bit and try it again.

But it works now in semi and in auto. Nice and crisp. The trigger seems a bit roughter then I remember,but it is not my gun so maybe it was always like that. but hey, it works now.

[CDN_Stalker]

Congrats! Good info to list.