Maruzen PPK/S cycling issue, blowback system help

[Bobovan]

Hi, my ppk has the issue of either firing a round or cycling the slide fully to load the next round, i.e. it will only cycle itself if there is no round loaded. I believe this is an issue with the floating valve in the magazine, but i don't know how they are supposed to operate, so i can't tell what's wrong. When compared to the magazine for the scorpion, the small brass valve has a beveled end on the scorpion but not the ppk, but that's the only difference i can find, scorpion cycles flawlessly...

can anyone familiar with maruzen systems explain in detail how they opperate? or if someone has had this issue and fixed it could you tell me how? thanks

[Bada Bing]

Re: Maruzen PPK/S cycling issue, blowback system help

Mine had an issue where the nozzle wouldn't return after firing a shot resulting in the slide jamming before clambering the next bb. Due to a small square piece of plastic on the roof of the plastic slide being worn away. As there wasn't that barrier in place the nozzle was free to travel too far out from its place and cause malfunction.

Does this sound familiar?

[Bobovan]

Re: Maruzen PPK/S cycling issue, blowback system help

no, thanks for the idea but it's still there...and it's almost certainly the mag, i tried reversing the floating valve and it cycled fine but wouldn't fire...whole of the slide's been apart, no wear, cleaned and re lubed

[Bada Bing]

Re: Maruzen PPK/S cycling issue, blowback system help

If it fires fine with the slide catch in the magazine disengaged? But won't shoot bbs? I'd say the mag valve is fine as its flowing the gas through the system.

Ok. Just to be clear. So you're bombed up with gas / bbs in the mag and you chamber a round, pull the trigger, click? What happens?

[Bobovan]

Re: Maruzen PPK/S cycling issue, blowback system help

ok, pistol gassed and empty mag slide catch disengaged it cycles fine, stops cocking the hammer when the mag starts cooling down but that's pretty standard. gassed and loaded with bbs, insert magazine and manually rack the slide, first pull of the trigger bb will fire at fairly high power but the slide will barely move, second pull of the trigger [with no round in the chamber] the slide will rack and load the next round.

forgive me if i'm telling you stuff you already know; basically there are two vents in the top of the mag and a brass sprung valve between them, the front one propels the bb, the rear one fills the piston chamber to cause the blowback. The valve rests blocking the rear vent, and by some pressure mechanism it moves forwards once the bb has left the barrel, opening the rear valve and causing the slide to cycle. for some reason the valve doesn't seem to move when there is a bb in the chamber...could this possible be the release valve not allowing enough gas through? what i need is someone to explain exactly how the valve is supposed to work, how the pressure works, so i can try and work our what's wrong with it

[Bada Bing]

Re: Maruzen PPK/S cycling issue, blowback system help

Yes you're right. The brass piece you speak of sits in its own plastic cage along with the spring in the rubber gas route. I've tried to replicate your issue on mine. Without that brass piece and spring in place, it vents the gas. With the brass valve in place without its cage, it operates with less blowback energy but still shoots bbs.

Do you have any other mags to try?

[Bobovan]

Re: Maruzen PPK/S cycling issue, blowback system help

i bought another couple of mags and they work flawlessly, but the blowback is much harsher, leading me to believe the fault lies in the release valve, which felt kinda stiff...i'm guessing an o-ring worked its way out of its groove or something, should be easy to fix now i know the issue is just that it's not getting enough gas

thanks for your help though, you're a legend for trying

- - - Updated - - -

i bought another couple of mags and they work flawlessly, but the blowback is much harsher, leading me to believe the fault lies in the release valve, which felt kinda stiff...i'm guessing an o-ring worked its way out of its groove or something, should be easy to fix now i know the issue is just that it's not getting enough gas

thanks for your help though, you're a legend for trying

[dadio]

Re: Maruzen PPK/S cycling issue, blowback system help

I have the China clone and have to keep the magazine gas release valve well lubed or I get this issue ,these valves are fully strip able unlike most so strip it lube it and try again ,in the old day's of 134a gas it came with lube included but most modern gasses are dry for some reason.

[Bada Bing]

Re: Maruzen PPK/S cycling issue, blowback system help

No worries mate. Sounds about right regarding the valve. Replacements are hard to come by without having to buy a whole new mag. When mine began leaking from those valves, I put them in a little zip lock bag with a little silicone oil and left them in an airing cupboard. Works a treat for shrunken/dried o rings.

Good luck with the PPK, it's such an adorable little gun.