ICS M4 Electrical Problems

[jond36]

I had a friend drop off an ICS M4 (don't know year or model). It had a few problems though:

 

1. When I tested the semi with an 8.4v 1600 mAH intellect battery, it shot semi mostly then a few auto shots.

2. Also the tension release foward assist would not work at all.

 

What can I do to fix these problems? Any thoughts or help welcomed.

[Stealthbomber]

Has it got plastic bushes?

 

If it has you'll probably find that replacing them with metal bushes will fix everything.

[RSM]

ICS M4 early models had an issue with the plastic bushings when worn the gun could very easily trip into full auto when in semi, only real way of checking is to whip the lower out if the date is unknown, any 6mm brand will go in though you might need to give the holes a very slight filing with some makes of bushing, either that or use a Modify installation tool.

 

Other things worth checking are the interface between the sector and the cut off lever as well as checking the spring is in place and the spring mount hasn't broken off the selector plate (Seen it happen).

 

As to the forward assist, check all the parts are there for it. The ARL arm should be obvious overhanging the side of the gearbox, on the other side of the FA knob inside the receiver should be a double ended Y looking plate that slides back and forth on the knob being pressed, one end should have a stub sticking down, this interfaces against the ARL arm, if its a case of the two parts not meeting then you can try shimming your ARL a little towards the right of the box OR bend the forward assist nub on that plate outwards a little.

 

 

[jond36]

Thanks. That helps. We'll take a look inside and get some metal bushings.

[jond36]

More problems

 

Before I even opened his gun. I hooked a fully charged 9.6v up to the gun and it shot like a 7.2v then slowly died after I released the trigger. I tried it again. Now the gun doesn't fire at all.

 

When I tried the battery on another gun it had incredible ROF. What gives?

 

Trigger contacts?

[RSM]

Check the motor, if it is a Turbo 2000 then that'll possibly be part of the problem if the trigger contacts aren't blacker than coal.

[jond36]

Motor is ok. Trigger contacts ok. I found that when the gun is on safe the interface between the sector and the cut off lever still touches the two prongs on the side as if it was still in auto. Hence the full auto during semi. How do I fix this? New Sector board.

 

 

[Stealthbomber]

Motor is ok. Trigger contacts ok. I found that when the gun is on safe the selector board still touches the two prongs on the side as if it was still in auto. Hence the full auto during semi. How do I fix this? New Selector board.

Did you actually take notice of the advice previously given?

 

Does the gun have plastic bushes?

 

The metal contacts on the selector plate (assuming that's what you meant by "selector board") have absolutely NOTHING to do with whether the gun shoots in semi or auto.

 

I'm a bit concerned that you don't really know what you're doing.

 

*EDIT*

Having read your edited post I'm now even more worried that you really have no idea what you're doing.

[jond36]

Ha, well it is only the 4th box I've worked on. I edited the post because I couldn't think of the word of the top of my head.

 

I forgot to mention I installed metal bushes. It's shimmed and the gears rotate fine. It seems electrical.

 

I am worried too

[Docv400]

Did you sort out the spring (tension) release?

The Anti Reversal Latch (ARL) has an extension arm added, as RSM explained.

The top should look like this;

The bar at the top my be distorted from the angle shown here, it should be at 90° to the side of the box.

The bar may also be missing, they can break off from the end of the arm.

[jond36]

Yeah the arm is ok. It just is not being hit by the upper arm. I am thinking it bent and I have to bend it back.