Maruzen MP5K GBB

CptJefferson

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Recently picked up a Maruzen MP5K with original box and manual.

Came with a leaky mag which I had already known but it’s the knocker valve that is leaky (every other part of the mag seems to be fine) from what I’ve seen online it’s usually the o rings around filler that tends to leak. Can’t seem to find any information regarding the knocker valve leaking and how to go about it.

Does anyone know where I can buy a replacement? I know the WELL G55 Is a clone of the Maruzens but even those I cannot find anywhere.

Im open to buying Maruzen and WELL G55 mags (maruzen preferably) but id also like to fix my current mag - are knocker valves fixable or would it definitely require a replacement?
 

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Maruzen guns are notoriously delicate and parts simply don't exist for them. You will want to baby this one you fix it, duster gas only.

They are beautiful once you get them running, but they are also absolutely wallhangers. It'll run crap in most games and you'll be risking damage it can't survive.

The mags you'll have to find a Japanese proxy for, they barely exist outside of Japan.

I'd try replacing the o-rings in the valve if it's leaking. If you have digital calipers to measure them it makes life much easier. It looks like a fairly standard valve tool should get it out.
 
Maruzen guns are notoriously delicate and parts simply don't exist for them. You will want to baby this one you fix it, duster gas only.

They are beautiful once you get them running, but they are also absolutely wallhangers. It'll run crap in most games and you'll be risking damage it can't survive.

The mags you'll have to find a Japanese proxy for, they barely exist outside of Japan.

I'd try replacing the o-rings in the valve if it's leaking. If you have digital calipers to measure them it makes life much easier. It looks like a fairly standard valve tool should get it out.
Thank you for the advice, i definitely wont be using anything but duster gas on it - i already knew how hard to it was to find parts but they really are non-existent (atleast outside of japan)

i ordered a set of mag seals for the mag, https://uk-airsoft.co.uk/product/well-g55-magazine-seal/ you reckon it would do the job?

being a bit of a collector, id hate for the original mag to die completely on me.
 
Thank you for the advice, i definitely wont be using anything but duster gas on it - i already knew how hard to it was to find parts but they really are non-existent (atleast outside of japan)

i ordered a set of mag seals for the mag, https://uk-airsoft.co.uk/product/well-g55-magazine-seal/ you reckon it would do the job?

being a bit of a collector, id hate for the original mag to die completely on me.
might as well try spec might be a little off.
 
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Finding a valve will be hard but LPE sell Maruzen SMG valve rebuild kits: https://www.leesprecision.com/o-ring-repair-kit-for-maruzen-smg-magazines
I've had a few LPE rebuild kits - always worked a treat!
 
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