First, let us say that some of the images that we've got are a little out of focus - most of them are OK, and they all should be good enough for you to see what we're talking about - especially if you've got your own PSG-1 in a state of undress......
Secondly, we (the 'writer' and 'engineer'), would like to say that we're not responsible for damage any of the stuff below might cause - it's all been put together with the best of intentions, but if you use our photos and info and your PSG-1 falls apart, blows up, burns you, causes a war, then it's not our fault.
This was the first of our PSG-1s (Jon's actually) to be upgraded and we thought we'd record the event for posterity and because there seemed to be nothing quite like a step-by-step guide anywhere on the net in English. We're just trying to put something back, that's all.
Thirdly, we not here trying to teach you to suck eggs - if we've said something that's obvious to you, we're sorry - if we say something that you know a better way of saying or doing, then we'd like to hear from you. We don't think we're perfect by any stretch of the imagination and, as far as this piece of work is concerned, we don't have an ego about it.
If you want all of the photos included, please mail the writer - I'll get them to you.
This is the procedure for upgrading a stock Tokyo Marui PSG-1 electric airsoft sniper rifle with a Systema Full Tune-Up Kit (FTK12). At the time of writing (August 2003) they retail for about £170 - and that would seem to be whether you buy one from a retailer in the UK, or have it imported from the US.
We will be not, however, be using the spring that comes with the FTK - as it will put the sniper rifle over the allowed 500fps and as we're going to be using this rifle in the UK, that would make it possibly 'illegal'. I'm not going to get into the semantics of whether this will be legal or not - suffice to say I don't know of an airsoft site in the UK that will allow you to play with an AEG over 500fps - so there's not much point of upgrading an AEG that you then couldn't use - IMHO. To be fair, the most fps I've heard of is something in the region of 550fps - but I've no idea how reliable anything over 500fps is ever going to be....
Anyway, whatever spring you put in, the procedure is the same - we're putting a Systema 200% spring in.
Firstly, prepare a clean area - about 6' x 3' in size is what we were working with. You can, obviously, do it in a smaller space - whatever space you've got, please try and make sure it's clean and you've got somewhere to put all the pieces that will be coming out of your AEG.
Take off the stock of the rifle, by unscrewing the retaining bolts, (P54 on the TM parts list I think). It goes without saying that all the pieces that you take off the rifle, should be put somewhere safe.....the lid of the FTK box is pretty handy for this.
Once the two bolts have been removed, the stock will slide off (with a small amount of force) - you might have to 'jiggle' the stock to get it come off, but it will come off. :-)
Unplug the stock and put it somewhere safe.
To remove the lower receiver, unscrew the screw that is recessed in the mag-well and then pull the lower receiver from the rest of the rifle. As you pull the lower receiver out, it will catch, internally, on part of the cocking mechanism. Use a screwdriver to push the lever out of the way. The lower receiver will slide gently out - DO NOT FORCIBLY pull the lower receiver out of the rifle - you will probably damage something.
There is a metal 'bung' that sits in the end of the lower receiver - if you can get this out before you seperate the receiver from the rifle, that's a Good Thing - if not, it'll probably come out when you pull the two apart. It's not fixed in so you won't damage it however you remove the lower receiver.
You should just have the lower receiver now.
Now is a good time to ensure that the receiver is 'decocked'. Failure to do this at this time might easily result in the loss of a) the spring, b) some other internals, c) one of your visual receptors (eyes).
Take the handgrip adjuster off - remember where the rubber washer sits. You'll be putting this back together, don't forget. :-)
Unscrew the retaining screw at the bottom of the handgrip and then slide off the bottom of the handgrip.
This will expose the motor plate. Unscrew the two retaining screws at the top and bottom of the plate. Don't touch the thing in the middle.
When you remove the plate, a small round metal disc will emerge too - this will prove to be a pain later, but you need to keep it.
The motor should be now exposed. Remove the positive and negative wires from the terminals on the motor.
Remove the motor - it should slip out very easily.
Inside the hand-grip, at the top, are two screws. Unscrew them and the hand-grip will come off - you will need to gently ease it off - be careful with the wires that run through the hand-grip. Make a note of where the wires pass.
The fire selector switch is the next thing to come off. Rotate the fire-selector switch to a vertical position - past it's 'safe' position. The switch is 'keyed', but you can prise the switch out of the lower receiver with your fingers.
Take note of the orientation of the selector mechanism inside the lower receiver - if it's not in the same place when you try to put the receiver back together, it won't fit correctly.
Remove the finger-grip from the trigger using the allen key that was provided with the PSG-1 when you bought it.
Remove the lower receiver 'case' which includes the trigger guard. This should slide gently off the internal piece.
The fire selector plate comes off if you (gently) pull it back, and then lift it from the lower receiver.
Remove the fire selector 'barrel' - carefully.
Unscrew the screw that holds the plastic switch mechanism to the gearbox and then slide the mechanism forwards. You'll be left with something like this.
Remove the two pins shown in the photo - they are different lengths, the larger one goes at the rear of the mechanism.
Once the pins have been removed, the gears and piston mechanisms can be separated.
There are three screws to unscrew.
PLEASE BE CAREFUL AS THE SPRING IS UNDER QUITE A BIT OF PRESSURE.
The entire assembly will come apart. As you can see in these photos.
By the time you've disassembled the piston/spring mechanism, your hands will be covered in sweat and grease. Now might be a good time to clean them and grab a cuppa.
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TAKE A BREAK NOW - you're existing piston assembly will look something like this.
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Use a very small amount of Systema Piston Grease on the replacement piston-head, and insert it into the end of the new piston.
Use a very small amount of Systema Piston Grease on the replacement piston before you insert it into the end of the new piston.
Exchange all of the Marui parts for the equivalent Systema parts and it'll look something like this when you've finished.
Before compressing the new spring, make sure your hands are as grease-free and dry as possible. This job just takes some effort and some reasonable hand-eye coordination.
Putting the metal clip on the outside of the piston assembly takes quite a bit of effort - like body weight. Be VERY careful not to bend the clip as you put it on - and before you put it on, please make sure that you're happy with the way you've put this assembly together - as you might not be able to get it off afterwards. YOU HAVE BEEN WARNED.
To be fair, we're not sure whether you need this metal clip or not - but it's been included for a reason, and we can only think that it's because it helps to keep the piston assembly in one piece during use.
Unscrew three screws (two Torx and one crosshead).
Remove the 'top' of the gearbox. Make sure that the washers from the gears stay with the gears - and don't stay with the inside of the top of the gearbox case. NB: TAKE A CAREFUL NOTE OF THE RELATIVE POSITION OF EACH GEAR WITHIN THE GEARBOX - we could be wrong, but they appear to need to be placed specifically relative to each other - if you get it wrong, the gearbox won't cycle properly, and the PSG-1 won't fire. If you think about how the top gear is actually pulling back the piston, it kind of makes sense.
Make sure you know which gears are replacing which gears.
Take off the top black plastic piece of the piston release assembly - ensure that you can note where the spring fits and which way round it goes.
Remove the cogs and the trigger lever.
Remove the plastic bushes from both sides of the casing - three from each. Replace them with the metal bushes from the FTK. The metal bushes should 'clip' into both sides of the case - you might need to use a small amount of force to make sure they fit properly.
The replacement washers are sized for each cog, so make sure you get the right washers for each cog. Apply some Systema gear grease to help stick the washer to the cog spindle.
Replace the original gears with the new gears from the FTK and apply some gear grease to the cogs. Refit the trigger spring.
As you replace the original gears make sure that they're all greased up and smoothly running. It is important to ensure that you put the gears back in the correct position - hopefully you made a good note of which position the original gears were in before you took them out.
Use the new metal shims that came with the FTK - they are size and cog specific - so be careful which ones you use. You might find it useful to use the manual that came with your PSG-1 - or you can download it from various places on the net. I've got a copy of the relevant pdf, but as I didn't create it, I don't think it's possible (from a copyright point of view) to reproduce it on a web page....sorry.
Don't be too stingy with the amount of gear grease you use - the gearbox needs to be able to run as smoothly as possible.
Put the gearbox back together once all the gears are in place. The observant among you will notice from this photo that we didn't get the gears back together in the right place the first time we put the gearbox back together - it's a total pain in the arse if you do this, so please get it right!
You should now have the two parts of the internal receiver ready to be put back together with each other.
The sequence of photos here shows them going back together. Once the two are locked together, put your PSG-1 back together again - the photos above should help if you can't remember what it originally looked like and which screws went where. Just take your time putting it all back together.
Be particularly careful when you replace the motor - that job can be a bit awkward and if you get it wrong, you could find yourself stripping the gear. :-(
You'll need to test your receiver now - whether you do that before you put the whole PSG-1 back together again or not is up to you. Either way - be careful. If it doesn't sound right when you pull the trigger, it could be because some of the internals don't quite fit properly - it'll be better to check them than strip or damage something. The FTK isn't cheap and you don't want to go breaking anything.
Jon dry-fired the receiver before putting the whole AEG back together again - which is just as well - as we didn't fit the gears in properly the first time.
We had some problems using an 8.4V 600mah battery - in that it didn't seem to have enough 'grunt' to cycle the whole mechanism reliably. This problem was resolved by using an 10.8V (or as near as it gets) battery. If you want to put a 12V battery in, you'll need to use the switch relay that came with the FTK - WE HAVEN'T DONE THIS - and probably won't. Jon is working out how to fit the switch though, but, at the time of this update (16th March 2004) he just hasn't had the time........
ALSO - Jon has modified his stock to accept the larger battery - I'm just about to do mine. I will try and take some pictures of the mod - before and after and post them here too......
We test-fired the upgraded PSG-1 after reassembly and it does appear to be much more powerful than stock - kind of obvious I guess.
We think that with a 200% spring, the FTK and a normal barrel, the PSG-1 will produce something like 500fps+.
With an upgraded barrel and a 180% spring, we've chrono'd both guns to around 480fps. Both of our guns gave extremely similar results (plus or minus 5fps for individual shots)
Well, we hope this has been of some use - either of us are happy to take feedback or questions. If you've got feedback about the technical process, try Jon first or myself if you get desperate. Jon's got a lot more experience than me in the mechs. If you've got feedback about this page, or my website, then mail me (or Jon if you don't get a fast enough response from me). :-)
We can't guarantee we'll respond (especially if you're being nasty) but we'll do our best - we've both got jobs so don't spend all day on the net......
