Ics m4 not cycling

[Alanh]

Its the sportline ics-45 c15

Piston broke, kid i bought it off replaced with one he bought, half plastic/, half metal teeth

Motor turns, gears turn when gear box is split, both auto and semi

When the top section is folded in, it just starts moving the motor a tiny bit, enough to know power is there but it doesnt pull back piston at all.

I opened the top gearbox, all looks good.

Bottom gears spin very well

Motor looks great, so does pinion gear.

Questions: could the piston be wrong kind and its locking the gears?

Could spring be too strong/motor half dead?

[Hectic]

Bad battery?
Piston moves freely without a spring in it?
Not sure how or if this is done on the split box but is the AOE good?
Motor hight is good? Even if it spins without load if the hight is bad the extra strain of pulling the spring could fuck it all up.

[Kos-Mos]

If you open your rifle, and press the trigger, the gears should do more than one turn.
If not, there is something wrong with the lower mechbox. A common failure is the bevel splitting (the conical section is made separate from the flat section, and they detach, causing binds and if they completely slip, makes a grinding noise).

You can also have a warped mechbox shell. (I saw 2 in the last years, with the newer batches just after the clearsoft wave).

You should be able to push the piston way back from the nozzle hole with a long metal pin/screwdriver. If not, you have a damaged piston or warped upper mechbox.

[HKGhost]

Make sure the piston isn't too thick in the upper gearbox. I've seen many pistons being thicker than stock, so it doesn't ride on the rails smoothly. Close up the upper gearbox with just the piston installed. Push the piston back and forth to make sure it moves freely. If not, you'll need to file down the rails a bit for it to fit.

[ThunderCactus]

since it's a split mechbox, take the spring out of it and see if you can move the piston back and forth in the assembled shell with your finger. If not, it's an oversize piston

[Alanh]

Ill see if the piston moves later tonight or tomorrow

Ill recheck lower gears to see if on semi they turn more than once.

Thanks for the input. I should have a stock tm piston i will try later if i cant find anything else wrong with it.

[Alanh]

Took it apart again, seems ive been stripping the pinion gear a little fooling arou d with motor height...

Anyway, the main issue seems to be with the piston. At the back of it, the gear teeth try to grip the piston behind the last tooth, and just set in to the plastic and locks the gears...

Looking at a tm piston seems to be the same size so im going to take out the cylinder, piston, the thing just in front of the piston (as theres a small crack in the m4 one) and report back.

[Alanh]

Update:


So seems the piston wasn't in the grooves as stated above.

Fires now, but motor making lots of grinding.... I cant seem to position it where there is none, and im wearing the pinion gear down trying. When i go too far out its just grinding and not cycling, and then motor just spins. Too far up, doesnt turn, when i do get a good spot the motor still seems to grind a bit... Ideas?

[ThunderCactus]

its probably right stripped by now
but normally I tighten it until there's resistance, then back if off half a turn and see where it's at

[Kos-Mos]

Originally Posted by Alanh

Update:


So seems the piston wasn't in the grooves as stated above.

Fires now, but motor making lots of grinding.... I cant seem to position it where there is none, and im wearing the pinion gear down trying. When i go too far out its just grinding and not cycling, and then motor just spins. Too far up, doesnt turn, when i do get a good spot the motor still seems to grind a bit... Ideas?

That sounds exactly like the broken bevel gear.
If you take your mechbox out, hold the "flat" part of the bevel with pliers and turn the beveled section. If it even moves, it's dead and needs replacing. If you can get a pinion puller or know someone who does it (most hobbyshops have the tool), you can replace only the bevel and pinion with better stuff. If will solve your issue.

DO NOT replace only the pinion or the bevel, ICS do not use the standard angle and will make a horrible noise with mismatched parts.

[Alanh]

To above, the grinding was more of a high piched whining sound. But i may open it back up and check the gear where the motor is just to be sure...

Yesterday I was fooling with motor height and adding a shim to the (motor gear), and considering the motor pinion is not perfect anymore...it works now to fire. Shot about 50-100 shots (still sounds more whiny then my aks but i guess normal) and seems hopup doesnt work, or a tm nozzle was added with ics hopup?

Also using old batteries not charged after the 50 or whatever on semi and some in auto, the spring wasnt being pulled back all the way and id have to press the spring release button, i think it worked a bit more on auto and then the same thing.

I thought to order a new 1 piece metal hopup, and file down the plastic clip if needed.

From internals it looks like it needs a reshim, cylinder head (guess version 2 the other is getting beat up), grease, and hopup+nozzle.