KWA/ASG M4 Problem

MetzgerMeister

Hi all,

As per the title, I have this gun and at the moment, it's not firing at all. When I pull the trigger is sounds like an electric drill.

Any idea what happened it? Hasn't been dropped or anything like that. It was working properly yesterday. No idea what happened.

Cheers,

Dave

Leftyflip

You've a stripped gear or piston by the sounds of it.

Puding

as Leftyflip said sounds like stripped gears/piston more than likely piston as the gears are still turning over freely

what battery where you using in it? normally with the kwa you get this when the 11.1v lipo is used and you get premature engagement of the piston shredding it

Masada

i'll have a go,

Collapsed bearing is my guess, (possibly spur gear bearing)

fayer

To quote a line a heard in a prominent Airsoft retail establishment when presented with a very similar issue....

"Run a few mags through it, it will be grand!"

J.D.R

Or, it might beyour Motor isn't connecting. Before you start stripping the gearbox, just tighten the Motor screw at the bottom of the pistol grip.

Markom5a

Masada wrote: »

i'll have a go,

Collapsed bearing is my guess, (possibly spur gear bearing)

Bet your right! Happened to me!

DICEMAN7

fayer wrote: »

To quote a line a heard in a prominent Airsoft retail establishment when presented with a very similar issue....

"Run a few mags through it, it will be grand!"

ahhhh fnuk it buy another

MetzgerMeister

I had a look at part of the piston that you can see where the mag goes in. What did I see? A big dirty crack

J.D.R

Yeah, its never good to have a big dirty crack on the piston

MetzgerMeister

J.D.R wrote: »

Yeah, its never good to have a big dirty crack on the piston

Ain't that the truth!?

I took out the rear retaining pin and had a look. This crack is going the whole way down the piston housing. Fcuk!

DeBurca

You should not be able to see the Piston without opening up the gearbox
Any chance of a photo of the crack

Masada

ahh you mean the dredded KWA gearbox crack?

is it like this?

MetzgerMeister

Masada wrote: »

ahh you mean the dredded KWA gearbox crack?

is it like this?

That's exactly it!

Masada

Your pretty much fecked, KWA gearbox shells are pretty hard to come by and the specs are a little different to that of your average V2 so it takes some work to use an aftermarket shell.

MetzgerMeister

Masada wrote: »

Your pretty much fecked, KWA gearbox shells are pretty hard to come by and the specs are a little different to that of your average V2 so it takes some work to use an aftermarket shell.

Just rang MIA (where I bought the gun) and they'll have KWA gearbox shells in next week Problem solved!

Masada

Good stuff, make sure its the new reinforced one though, you'll notice its about 3-4mm thicker either side the cylinder where yours cracked. no point in fitting another one the same as the one in there. the failure rate on those is ridiculous.

MetzgerMeister

I really would prefer if these kind of expensive guns were made properly using proper materials that don't break. Yes it would hike up the price but it's better to do that than having silly things breaking all the time :mad::mad::mad:

Leftyflip

Were you using an 11.1V lipo?

MetzgerMeister

Yes sir! I've had the gun for 2 years now and never had any mishaps with it up to now.

Leftyflip

einheisserschre wrote: »

Yes sir! I've had the gun for 2 years now and never had any mishaps with it up to now.

That's why it happened, they'll last longer with a 7.4 imo.

DeBurca

Leftyflip wrote: »

That's why it happened, they'll last longer with a 7.4 imo.

I have to disagree on that, the piston teeth and gears will last a lot longer on a 7.4v lipo then a 11.1 lipo but the damage to the front of the gearbox is strees fractures due to the repeated impact of the piston head with the cylinder head
The energy transmitted to the gearbox by the impact of the piston is generated by the spring and is not affected by the voltage in the battery
The extra voltage in the 11.1v lipo will cause there to be more impacts in a given time frame then a 7.4v lipo but the damage is still caused by the energy transmitted by the spring and the spring alone

Puding

7.4v instead of 11.1v, less rof so less impacts per second from the piston head slamming forward gearbox hopefully should last longer

many factors come into play , heavy spring ( used with ported cylinder to give low fps high rof and stop premature engagement but speeds up damage), weather ( if its cold metal becomes brital and chance of damage increases ) rof ( higher rof more impacts higher chance of damage

but lower rof does = less stress, so a lesser chance of damage or longer before critical failure, at a fundamental level

you disagree but your both saying the same thing really

this issue also comes up with drill cylinder as there still pulling the heavy springs, colder weather came around this year and had a few creaked shells cross my work bench

Masada

I put this down to the springs and shells as opposed to the battery, Just like Deburca,

I've seen em do it within the first week, or some last a lot longer but the net result is a weak shell will always break in the same place, thanks to the overly generous springs in there, metal piston heads and of course the weak shell.

Most of these have been addressed though and the newer line has been an awful lot better, so far.

Puding

agree the spring heavy spring and the impact is the cause and faulty design can cause the gearbox to fail faster but the point i think Leftyflip was trying to make was that a lower voltage batter can increase the life span of the shell that is all

the fact that this shell lasted two years to being with points to it being one of the good ones and a lower rof battery more than likely would have meant it lasted longer, but it equally come down to it being used over the cold winter we had, swings and round abouts really

as with most things in airsoft its not down to one thing but the sum of the parts and factors, why i always quote airsoft repair work as being more akin to the dark arts

elDiablo79

mine broke and i only ever used a 9.6v, but it did break in november on bleedin ice cold sunday.:D

MetzgerMeister

Puding wrote: »

the fact that this shell lasted two years to being with points to it being one of the good ones and a lower rof battery more than likely would have meant it lasted longer

I used the 11.1 Li-Po since I got the gun. Never changed only to a second 11.1 Li-Po. Same as the one supplied with the gun

AirsoftEire.com

Element make a new style cylinder head for v2 gearboxes whereby a rubber ring is built into the outer edge and rests against the gearbox. It absorbs some of the impact and puts less stress on the gearbox casing. Something all KWA owners should consider.

Steve