Ics m4 not cycling properly

[ghostwalker]

Having addressed the problems with my l86. I now turn my attention to my ics m4.

It's a little hard to explain the issue and if a video would be more help please say so.

My m4 has an erratic problem with the way it seems to cycle (not on a bike I might mention).
When you pull the trigger on occasion it will fire and cycle fine, but then for no apparent reason it will stop. When the trigger is pulled you can hear the gears/motor turn, but it's almost like the whole cycle doesn't complete and there is no 'release' or 'pop' of the gun firing. If you pull the trigger further times, there will be a click but no movement action.
If you then press the forward assist button, you will hear the gears release. The gun will then either shoot or start the problem again with the sound of a 'half' cycle and then nothing.

I tried replacing the fuse, a fully charged battery, changed out the spring and piston. But none of these have helped.
I'm not the most familiar with m4's but trying to learn and trying to sort this out before surrendering it to a tech.

Any advice muchly appreciated.

[colinjallen]

Re: Ics m4 not cycling properly

Is it doing this on both semi- and full-automatic?

[ghostwalker]

Re: Ics m4 not cycling properly

If it starts cycling in full auto it seems ok, though I haven't put it through any really prolonged bursts of firing.
However if it's already having the problem, switching up to auto won't do anything to help.

[ghostwalker]

Re: Ics m4 not cycling properly

In an effort to better explain the problem...my poor attempt at a video

[Sitting Duck]

Re: Ics m4 not cycling properly

not sure atm....

lockup with receivers together could be motor height or mechanical issue with lock up

lower half of gearbox only at about 0:53 the cycle is not completing 101%
semi you should see just the sector gears to spur showing - no piston teeth visable
but around 0:53 one or two pulls it stops with the sector's piston teeth showing ???

may I say - don't slowly pull the trigger but positive pull - not with brute strength
but a very slow pull will start to turn over but a worn trigger trolley may not latch cut off under trolley correctly
hence she starts to run but not stop at first 101% of time

I'm off out the door but seems you could have 2 x different issues on actual gun

1 gearbox locking up
&
2 trigger trolley or cut off lever - maybe selector but think selector is operating correctly at first glance
so think trigger/trolley may be worn and jumping off perhaps
BUT normally this would happen on full auto as well if trolley slips off trigger.....

but deffo that trigger trolley & cut off is not operating as it should
ps- mega thanks for video it really helps and will watch more later

yeah cut off trolley related issue is my guess but I'm off out for a while

[sparrowhawk]

Re: Ics m4 not cycling properly

Yaw lever,and probably worn trolley that's your problem,it always those that caused me these issues in the past with my Ics m4s