Was my spring cut?

King John The Last

Just opened the gearbox of my JG AUG for the first time today and noticed this. I know that it was downgraded. This is the first gearbox that I have opened. Should I be getting a new spring?
http://i51.tinypic.com/30lnuon.jpg (bigger pic)

thermo

that looks "snapped" as opposed to cut, was there any other bits of it in the gearbox?

King John The Last

Definitely not. I opened it on a tray and there is no other piece here.

thermo

it looks odd,,,,,,,,,, what was the fps before opening?

King John The Last

260 if I remember right. You cant really see this in the pic, but the last (loop) on the spring is smaller and irregular to the other loops. Also, the whole spring is curled towards the cogs on the piston

thermo

id change the spring, QAS do some good quality m90's maybe drop them a line.

Leftyflip

Yeah - those stock springs are crap tbh - they shear, bend, twist, etc.

Get yourself a Guarder SP90, and make sure you have maximum compression between the piston and cylinder - you should get 320 easily. Or a safer bet is to use an SP85, with good compression you'll get 310-315.

King John The Last

Leftyflip wrote: »

Yeah - those stock springs are crap tbh - they shear, bend, twist, etc.

Get yourself a Guarder SP90, and make sure you have maximum compression between the piston and cylinder - you should get 320 easily. Or a safer bet is to use an SP85, with good compression you'll get 310-315.

Maximum compression? *scratches head* I dont know much about the technical side of airsoft:o Explain please?

Leftyflip

King John The Last wrote: »

Maximum compression? *scratches head* I dont know much about the technical side of airsoft:o Explain please?

Apologies my friend!

Presuming the gun is still in bits, take the cylinder assembly and cover the hole in the cylinder head. Then push the piston in, if it goes in with no resistance, you've no compression (ie, no airseal in the cylinder), if it takes a lot of effort or doesn't move at all inside you have good compression.

King John The Last

Id say its about medium resistance. What should I do about it?

Leftyflip

King John The Last wrote: »

Id say its about medium resistance. What should I do about it?

Silicone oil and PTFE (Teflon tape) wrap some tape around the cylinder head to improve the seal there and then lube up the o-ring on the piston, should improve the compression.

King John The Last

Thanks for the help, I will continue this tomorrow when I am fully alert:D I had a hairy moment with the trigger assembly already.

King John The Last

I sealed the leak between the cylinder head and the air nozzle but I dont notice any difference in fps (I dont have a chrono) Might that mean a leak between the nozzle and hop chamber? How would I test/solve this?

Would this spring do?

T4RGET

I find the Guarder springs pretty decent, I got mine from SEairsoft so that one could be it, there's no brand on it. Like Ger (lefty) said you're gona need a new spring either way even if you have fixed the compression

MonkeyGuy

I would use the term air seal there. Dead right though, PTFE tape or similiar is an excellent investment.

EDIT: It could, you can also use PTFE tape between the hop-up and barrel and the hop-up and gearbox. That'll give you some more FPS.

Be careful picking springs because you should push yourself over the limit. It's better to have lower FPS and perfect seal than high FPS and air pitting out in all directions.

King John The Last

My Aug always had a minor double feed problem, but since I opened it up it got a lot worse. On semi it is more likely to double feed then not. Its not as bad on full auto. I think it gets worse as the battery loses charge but I have to confirm this. If I put the gears back at the wrong rotations, would this explain it? Any other suggestions?

King John The Last

I just changed my barrel from a 6.03 tightbore to a TK twist barrel and that seems to have fixed it, havent a clue why

Inari

King John The Last wrote: »

I just changed my barrel from a 6.03 tightbore to a TK twist barrel and that seems to have fixed it, havent a clue why

Most of the time feeding issues post-upgrade are because of re-assembly. Odds are you just put it back together better when putting in the TK-Twist barrel

MonkeyGuy

It's likely the hop-up rubber wasn't seated right or something. If you didn't open the gearbox when replacing the barrel then it couldn't have been the gears or air nozzle or that. Anyways, it works now, don't complain! :P