Maruzen P99 GBB

[TheBauer]

ok people ive had nothing but problems with this pistols its a shame...

 

this happened a while ago and when i bought a new mag and gassthe gun started working properly again, but after my last skirmish (may) the blow back just doesnt work properly.

 

first of all the slide when i pull the trigger only goes back about half a cm. if i pull the slide back i notice little friction but no more than normal.

 

ive tried stripping my pistol down, soaking parts of it in warm soapy water, leaving to dry then using silicone lube to lube it all back up as i put it together.

 

but still no luck,

if i hold it upside down and fire i get more a blow back but still not strong enough to lock it when the mag is empty.

 

ive used appy preditor ultra gas and im currently using cybergun blowback gas.

 

any ideas people?

[Hvy gear]

i have the exact same problem except i can get one shot off before it stops blowing back propley what ever i do i just can't seem to solve the problem.

if anybody has the solution please let us know.

[Blazer]

Okay... Don't Panic.

 

First, lock back of slide.

 

It is either too much lubrication, or worn slot.

 

The latter can be fixed by using an epoxy resin, IF you have the skill. The former just requires you clean the gun and only use a light coating of silicon spray.

 

Next, can you hear gas escaping from the magazines?

 

Do the magazines have their rubber seal at the top of the magazine?

 

Both of these will adversely affect blowback, as will dirt.

 

Also, using more powerful gas will shorten the life of your toy gun. The seals are only rated for 134 and you increase wear by using more powerful gases.

 

Anyway, escaping gas means seals that are not working. Dissaemble magazine and lubricate all the seals. Replace any that are misshapen. Do not screw things back too tight, otherwise you will strip threads and ruin seals.

 

Good luck.

[TheBauer]

Okay... Don't Panic.

 

First, lock back of slide.

 

It is either too much lubrication, or worn slot.

 

The latter can be fixed by using an epoxy resin, IF you have the skill. The former just requires you clean the gun and only use a light coating of silicon spray.

 

Next, can you hear gas escaping from the magazines?

 

Do the magazines have their rubber seal at the top of the magazine?

 

Both of these will adversely affect blowback, as will dirt.

 

Also, using more powerful gas will shorten the life of your toy gun. The seals are only rated for 134 and you increase wear by using more powerful gases.

 

Anyway, escaping gas means seals that are not working. Dissaemble magazine and lubricate all the seals. Replace any that are misshapen. Do not screw things back too tight, otherwise you will strip threads and ruin seals.

 

Good luck.

<{POST_SNAPBACK}>

to much lube? damn never thought that be a problem tho i dont think it is. i cleaned my gun right down and lubed it bk up when i put it bk to gether, hardly any dirt on it.

i have no gass escaping from the mag

they still have the rubber seals at the top of the mag, ive removed and lubed and put them back in

 

lets talk worn slot.... please explain.

[Shao14]

You still have that problem, eh? I really have nothing new to add except re-iterate http://www.arniesairsoft.co.uk/forums/inde...topic=14534&hl=

 

Hold the mag up with your off hand.

[TheBauer]

when holding one mag up the slide doesnt go back into position proberly

with the othermag it does

 

but still no blow back hard enough.

 

the problem went away once i got a new mag, and both mags worked. but the problem came back

[Hvy gear]

you might need a new recoil spring.

 

i broke the end washer on mine - does anybody know where i can get a new one?

[TheBauer]

to be honest mine is half snapped...

 

at the end of the spring where it clips onto your chamber bit the end circle that looks like (0) is snapped like :::: (0 it still holds its position on the camber but i dunno that cant be the reason it doesnt work properly, nothing is out of place

[justinkim]

The Maruzen P99 has a problem with the magazine catch wearing out. When this happens, the magazine is no longer held tightly enough in the mag well. This problem is easily fixed by replacing the Maruzen mag catch with a real steel catch. The real steel catch drops right in to the Maruzen frame. You'll have to hold on to your original spring - the real one is a little to fat to fit properly.

 

Replacement catches can be ordered here: http://www.carlwalther.com/

[12bore]

i also have a maruzen p99 which i was going to sell to the bauer but i also have had no end of problems with it the mags do not feed right i have cleaned it tome and time again, the blowback does not always work and it does not always lock after it has eventualy emptied the mag.

[Hissing_Sid]

Just bought one of these (with this problem) and I found that the problem WAS, as Shao said, that the mag was sitting too low in the mag well.

 

On mine the paint hadn't even worn off the mag catch so the problem is NOT that the catch wears. It's that it's not exactly the right shape to begin with.

 

The design of the magazine doesn't help things.

TBH, Maruzen had a chance to compensate for this problem with the mag design. The gas reservoir is in an alloy block which slips inside a steel sleeve. IF Maruzen had left the alloy reservoir "loose" inside the steel sleeve then the owner could slip shims (cardboard, plastic etc) underneath the heel-plate to elevate the gas valve to the correct height.

Unfortunately, however, Maruzen saw fit to design the mags so a pin goes through the alloy reservoir AND the steel sleeve. This means that there's no way to elevate the reservoir inside the steel sleeve.

Bummer.

 

Anyway, I would have SWORN that mine wasn't leaking gas anywhere until I tried pressing the mag up a bit. It makes a clean "blat!" with every shot. You can't tell that the mag isn't sealing by listening.

 

The Maruzen GBB chamber is quite nice. It just uses a brass plug in a plastic tube which means there's no danger of any O-Ring problems.

One thing I noticed was that the brass plg was loose inside the GBB chamber. There's a chromed cast-iron lug at the back of the GBB chamber. The brass plug is supposed to be pressed into place over this. If it's loose in the chamber then you'll need to strip down the slide to put it back in place.

 

The slide is pretty complex to strip down but there are no really tricky parts. As long as you see where all the parts and springs come from as you take it apart then it should be straightforward.

 

Another reason to take the slide to bits, of course, if to check that the GBB chamber isn't actually split.

 

If all else fails then WGC sell a TK "blowback improver" for the P99 which replaces the brass plug with a cup seal so, theoretically, less gas will be needed to achieve the required blowback.

 

Dunno if I just got lucky but I ended up just heating up my mag catch and hammered the ###### out of it to change its shape slightly. It worked for me. I'll whip it back out and take a picture showing how I altered the shape in a while.

 

[edit]

FWIW, mine still tends to do stuff like double-feed or misfeed quite a bit. I love the gun to bits but I would never take it anywhere near a skirmish. This is definately one for fondling while watching TV rather than skirmishing.

[Sale]

New Maruzen GBB's have the switch valve in the top of the magazine instead of the nozzle. Check that the switch bulb moves freely to both positions. Too much lube will hinder the operation. Try to get it completely dry, reassemble and try it out. The problem might not be in the gun at all.

 

-Sale

[Hissing_Sid]

New Maruzen GBB's have the switch valve in the top of the magazine instead of the nozzle. Check that the switch bulb moves freely to both positions. Too much lube will hinder the operation. Try to get it completely dry, reassemble and try it out. The problem might not be in the gun at all.

 

-Sale

<{POST_SNAPBACK}>

Sorry. I don't understand what you mean by "nozzle".

 

My 2 mags have the switch valve inside the rubber seal on the top of the mag.

[TheBauer]

hey sid i like the brss lug thing i notice now that it should be back slightly. so im curretny stripping the slide down and im gona disasbemble the bb system n put it into place... let you know in 15mins or so the outcome

--

edit:

 

well my brass plug doesnt fit over the iron lug it just buts up against this.... is it ment to be fixed iver it??

[Hissing_Sid]

FWIW, here's the pic of my "modified" mag catch.

 

Basically, I sat it on a bench and hit it with a small hammer in the direction of the black arrow.

 

The original shape is in green. The final shape is in red.

 

The result, as you can see, is that the mag needs to be inserted slightly further before the catch engages.

 

[edit]

As usual, forgot the damned pic.

[TheBauer]

well ive just glued the bras plug to the iron lug putting back together now

[Hissing_Sid]

Was the brass plug loose?

 

I found that mine was a fairly tight fit so I just pressed it back onto the iron lug.

[TheBauer]

well mine butted up against the iron lug but the brass peice moved freely under the plastic bit... hold on think i have some photos

 

--

 

nope i deleted them

[TheBauer]

well ive reasembled. with the brass plug glued into place on the iron lug... still same problem.

 

if i push the mag up (holding it) then the slide kicks back the same little bit but wont go forward properly

 

i think im gona buy another GBB

[Sale]

Sorry. I don't understand what you mean by "nozzle".

 

Ever heard of a loading nozzle? All modern GBB's have one.

 

My 2 mags have the switch valve inside the rubber seal on the top of the mag.

<{POST_SNAPBACK}>

 

Exactly like I said. Too much lube there will cause malfunction of the blowback. I fixed my mates P99 by changing the mag catch to a real one and thoroughly cleaning the switch valve and leaving it without lube.

 

-Sale

[TheBauer]

so this brass plug... was it ment to be loose? lol

[TheBauer]

well i appear to have found the problem

the back of the slide the semi circle shape bit that slides out allowing u to get to the indicator pin, spring n some other grubbin. took that out now it blow backs fine

 

so means i gota work out whats wrong with those peices and fix accordingly lol.

 

--

when i say properly i mean it blow backs fully on 8 / 10 shots.

 

andactualy that only worked for 5 mins now im back to first base.

[Hissing_Sid]

If it's doing the "only blows back 5mm" thing I'd bet my house that it's gas escaping somewhere. Probably in the joint between the mag and the GBB chamber.

 

I tried mucking about with the switch-valve that Sale is talking about. It did make the gun fire wrongly but it spewed a cloud of gas out at the same time. If this ISN'T happening then it's probably not the switch valve.

[TheBauer]

If it's doing the "only blows back 5mm" thing I'd bet my house that it's gas escaping somewhere. Probably in the joint between the mag and the GBB chamber.

 

I tried mucking about with the switch-valve that Sale is talking about. It did make the gun fire wrongly but it spewed a cloud of gas out at the same time. If this ISN'T happening then it's probably not the switch valve.

<{POST_SNAPBACK}>

yup 5mm to 1cm blow back problem, ive tried using little rubber slips to raise the the rubber bit on the mag but that failed to work.

 

to be honest i think im going to sell it on.

ive got a few extras. no problems with mag leaking or anything so.

----

 

also now its firing a shot of gas when i pull the slide back...

 

youll see this inthe for sale section soon.

 

tis up for sale now with extras gooo look