Maruzen M1100 piston/cylinder assembly help Pic heavy

[Payback]

I have purchased (i know, bad idea) an m1100 recently that had some issues. Well, i've fixed nearly all of them except for one major one.

In the photos below show the area i'm having trouble with, and the part i think is the issue. The main issue is that this gun has been opened up before and rigged up half a$$ and slapped back together (was only told to me it leaked gas).

I have put in a new piston head (as seen the white part) and fixed all gas leaks.

Basically what happens is, i load gas in the mag, pull the trigger and it all expels out the cylinder (from where the red arrow points) without moving the slide back at all, or very little.

The spring i'm not sure if it's original, or was tossed in as a fix from whoever tried to fix it. I'm not even sure if it's all installed the correct way. It doesn't seem to move anything, i'm not sure if it's part of the issue from not allowing it to close the system.

If i put my finger over the hole in the end (red arrow again) it works as it should, but i can't really put my finger in the gun to get it to shoot

Does anyone know what i should be looking at? Or know how the piston/cylinder assembles correctly? I've searched for a week now trying to find something in detail but can't seem to find what i need. If more info is needed of what it's doing let me know and i can try to explain it better.


piston, cylinder, and slide all assembled.



other side of same group



Showing how it slides when trigger is pulled.


piston/cylinder front where back of shell sits


Top of piston/cylinder open with nozzle deal and spring


Inside of cylinder showing piston


showing parts and the spring and nozzle deal.

[Nodachi]

Sounds like the trigger mechanism. The trigger on the M1100 is notoriously weak, and even the stock one will slowly let air out if you don't give it a firm positive pull. If your trigger is somehow not hitting as hard as it should, that could be the problem. (Actually, I'm not 100% sure, but I think your hammer spring is backwards. I think the metal part is supposed to go on the bottom, with the spring directly contacting the hammer, odd as that is.)

Barring that, not sure. I'll dig around for some more stuff on Japanese sites when I get the chance.

The 1100 there isn't as much info as the 870 unfortunately...

[Payback]

I tried to put the spring in the other way, won't work, just falls inside the piston. The trigger presses the valve fully open when pressed, I've even removed the spring bushing thing in the trigger that was suggested ,on a very in depth write up, to correct trigger issues. That spring pictured looks home made to me. Mainly I was hoping somebody who had one could compare to see if I'm missing anything, our if it's assembled correctly.

[Nodachi]

The only good pictures I can find are on http://adf01f.blog136.fc2.com/blog-entry-37.html this blog.

It mostly talks about the operation of it, rather than the disassembly.

I can translate the captions if it helps.

[Payback]

I can see i have one spring backwards from those photos. That helps, but the insides are the problem still. I'm just gonna have to try a bunch of different ways to see what works.

[Payback]

so i put it back together and thought that maybe i wasn't getting enough pressure through it. So rigged up my compressor and put it at 50psi, nothing, went up to 120psi and it cycled properly. Just need to fix the extractor now so it doesn't stove pipe anymore.

[millettepatricia]

You should visit once this blog http://adf01f.blog136.fc2.com/blog-entry-37.html...you can find here nice collection of pictures..

[Payback]

Already sold it. And can't read the language on the page you linked.