ICS M4: Inconsistent Firing

[Heimdall]

Hey Docs,
I'm hoping to get some suggestions thrown at me as to what's wrong and what I can do to fix it.

Here's my problem: my aeg will fire consistently for about twenty minutes and will then start double firing BBs or jamming. The mags, mag well, and BB intake are perfectly fine.

I've only used Airsoft Central BBs for the most recent games so I'll be testing it with bastards and mad bulls while I wait to hear what you think.

ICS M4 Parts

• stock motor
• reshimmed and clean gears
• polycarbonate piston cylinder
• plastic piston head (the air seal isn't perfect but it's pretty tight)
• S120 spring (I've used two S120 springs to test the integrity and they're both consistent)
• 363mm Madbull 6.01mm tightbore inner barrel
• stock hop-up/ New rubber
• LiPo battery and NiMh Stick battery

All help is appreciated.

[Rusty Lugnuts]

Just wondering- how long before it will work again? During the time it's acting up-with no mag in and dry firing on full auto does the rate of fire seem different?

[funkyboss]

Did you change the nozzle? (Apparently not but just in case)
Maybe the tappet plate spring is weak, or the tappet plate lacks of lubrification?
Does it fail during semi or auto firing?

[Rabbit]

My ICS M4 started fucking up the same way - sputtering when firing - when I used an S120 and 7.4v Lipo 1000mah -it wouldn't happen right away but only after playing for a bit.

The issue was solved when I changed out the spring to an s110 and I was fine.

I find that the ICS stock motors are pieces of shit and the pinion strips way too easily - I use the JG Blue HighTorques with flawless performance in all my ICS AEGs.

[MASAKO]

Sometime BB bastard could cure that kind of problem. I suggest you to use other brand of BB first befor touching something else. Hope it help.

[Heimdall]

@RustLugNuts - It will fire consistently in either semi or full auto for approximately 300-400 rounds. After that it will start double firing and even jamming.

@funkyboss - my internals seem fine. The tension on the tappet plate spring hasn't changed. It doesn't fail completely in either setting; both are fairly consistent.

@Remylebeau - I'm planning on picking up a high torque motor to upgrade from the stock so hopefully that will help. It does sound like its pulling too hard sometimes.

@MASAKO - absolutely. I'm going to try it tomorrow with some new BBs and hopefully all will be well.

Over the next few days I'll also look for a new high torque long motor.

[Rusty Lugnuts]

LOL that's not what i asked, I was trying to nail it down between a mech box issue or electrical or hop up issue. Anybody can basically shout out parts, you need to ask questions that eliminate potential trouble spots... so here's another thought - the battery ,when the gun acts up is the battery hot? if so when it cools down is that when the gun shoots fine again? Have you tried a different battery with the same result?*Listen to the gun's rate of fire with no mag in when it's fine and again when it's acting up --does it sound the same? IF so it's probably not a mechbox issue.

[Heimdall]

Eiminating possibilities is always on the top of my list for repairs as it should be. After feeding about 500 bbs through multiple mags on full auto and semi with both of my uppers, I stripped it and found that one of my tappet plates was destroyed. My secondary upper seemed to feed decently so I'm going to do a serious stress test and see if it persists.