ICS M4 Intermittent misfires

[Mikep81]

Guys Ive got an ICS M4 that intermittently misfires. Sometimes I'll fire 20+ rounds and then suddenly nothing for 5 or so pulls of the trigger sometimes it won't fire anything every few rounds. And it will always correct itself after a few blasts of the trigger. Upon inspection it appears that the tappet plate and nozzle are, at times, not coming back far enough, if at all. Now is this a Tappet plate issue or a gear issue? I can't see anything wrong with the gears and likewise the tappet plate doesn't seem too worn. It is an ex rental though so has had a fair bit of abuse. Any ideas before I start replacing parts?

[sj_asc]

Re: ICS M4 Intermittent misfires

When you say nothing, do you mean the gears are cycling but nothing is feeding? Or is there just no response from the trigger?

[tsv2tuff]

Re: ICS M4 Intermittent misfires

sounds like a worn tappet plate. assumeing you mean wont feed by "wont fire"?

[Mikep81]

Yeah sorry it won't feed. I've had my hand over the barrel while firing (obviously without the mag on) and can still feel the air pressure. But I can see that sometimes the nozzle seems to stick rather than pulling back to feed a round.

[sj_asc]

Re: ICS M4 Intermittent misfires

It's probably a worn tappet plate as said.
As for nozzle position, the gears rarely land precisely in time when the power is cut which is why often the nozzles resting position can be random, even with semi auto.
With the upper gearbox removed, you will be able push the nozzle in and see if it's still attached to the tappet plate, and also checking that it is returning positively.

[Mikep81]

Yeah I've checked the gearbox and the nozzle is attached fine and it all returns as expected after pushing back. It just at times doesn't seem to move or seems to get stuck when firing. I'll get a new tappet plate and see if that sorts it.

[Mikep81]

Re: ICS M4 Intermittent misfires

Just to update this, when checking the tappet plate against pictures of others on the internet it looked like mine wasn't worn at all, so I decided to do some more digging. I took my mags apart again and gave them a mega deep clean but didn't solve the problem, after wiggling around the magazines I could get it firing but still no joy on some midcaps. I read somewhere about putting a strip of velcro in the mag well and viola, all my mags work and problem solved!!

[-=256=-Swerve]

Re: ICS M4 Intermittent misfires

I was just about to post about mags

I had the exact same firing issue, narrowed it down to a couple of my non ICS mags

[Mikep81]

Re: ICS M4 Intermittent misfires

I was just about to post about mags

I had the exact same firing issue, narrowed it down to a couple of my non ICS mags

I didn't even think to check the mags to be honest. I just assumed that they'd all work normally, but hey ho, everyday's a school day!

[-=256=-Swerve]

Re: ICS M4 Intermittent misfires

ICS guns can be picky with mags