Tonight, I removed and opened the factory microswitch (made by XURUI, XV-152-1C25, 20A, 125/250VAC) . It's a piece of crap!

First of all, the plastic casing is not heat resistant. The contacts are not made of copper, only copper coated. I discovered serious burning marks, down to the bare metal. I repaired the switch (temporarily, until better replacement) and installed an extra part to reduce spark formation.

I also inspected the hop-up, it's dog eared after 5K rounds. Any recommended brand for replacement?

Im gonna have to experiment on the nozzle. Im gonna mod the nozzle making notches/channels so that when there is a jam in the hopup that the nozzle doesnt make a perfect seal with a bb...so that the piston could move all the way forward. Im gonna have to make sure fps and accuracy doesnt get affected much.

Any inputs?

Does the ca249's nozzle have a cross shaped indentation within the inner diameter of the nozzle? If not, I'd suggest this.

yes it does. maybe its not letting enough air out fast enough when there is a jam.

Anyone had problems with the fuse blowing frequently? Just test fired mine - fuse blew right away (out of the box). *lol* Changed to a new 25A fuse... seemed to fire fine. I put the stock back on, it stopped firing. So I checked the fuse - busted again.

I'm going to try a stronger fuse, otherwise bypass it altogether.

Guess it's something else to watch out for with the CA249.

EDIT: Oh, I was using a standard 8.4v 2400mAh large battery.

update

Well, after some trouble with piston and gears, my CA249 is shooting great. Chronoed at 360fps with 0.25's. ROF was excellent. I shot about 3000 rounds today at a game.Not a single problem. The battery was still going strong. The box mag fed really good. No misfeeds or jams. I sprayed some silicone oil into the hopup chamber before the game to help prevent jams. Internally, the piston is in excellent condition. No signs of wear *knock on wood*. Now Im happy.

I downgraded to 8.4v 3300
Current mods:
prometheus gears (for MS100 / MS110 Spring)
TM stock piston
systema pom piston head with bearings
m120s
systema m16 tightbore
systema NB cylinder

phalanix,

Sounds like a f**ed up battery, or the wires shorted on something. The stock can peel the wires, it happened to me (but no fuse popped).

Battery's fine - I use it in my other AEGs. It may be the wiring - but haven't had time to check internals yet. I did buy a set of stronger fuse, haven't tried it out yet either.

And yup, my stock had peeled a bit of my red wire as well.

Any idea on the outer barrel thread type?

Positive 14mm.

After 10k rounds, I chrono'd my 249 and it's only 270-280fps with .25BB +SP110 spring (290-310 with SP120). Pretty bad air leak, eh? I have no experience in fixing leaks, what you guys recommend?

silicon oil first. Heavy stuff works nice. Around the cylinder head and any O rings that you can find.

I took apart the aug after about 20k and did that (and at the same time a piston upgrade), everything improved after the oiling.

Well that can't be a huge air leak. I mean, even on that spring - the 110 I mean - if it's shooting 270-280 with .25s thats what? Nearly 320-330 with .2s if I remember correctly? And 290-310 with the 120 would probably be close to 350-360 with .2s. I could be wrong because I'm not really too familar with the Guarder springs, I've only used the Systema and PDI ones.

But after 10,000+ rounds (Especially continuous like in a SAW) I would definitely go with lubing up the entire mechbox internals, especially the cylinder walls, piston head o-ring, and the hop bucking with the appropriate greases.

And if you do pull the box apart, pull the cylinder out and try to run the greased piston up and down the cylinder while holding your finger over the air nozzle hole - if the piston is hard to push into the hole, you're getting a good air seal on that end.

I'm currently waiting to join the CA M249 club myself - if only they'd hurry up and release the Para.

Has anyone had any more problems out of the microswitch? Or are they doing any better?

Thanks for the tips guys.

Should I order gearbox/piston greases made for AEGs, or I can use anything that is not too thick and not petroleum based?

I use spray lithium white grease for any of my internal stuff - both cylinder, piston and gear grease. I've found it makes excellent seals and keeps good lubrication on the gears. I've also found that when I use lithium grease, it actually gets the gun a tad few more fps than guns just lubricated with normal AEG type grease. I found my huge spray can of Lithium Grease at an automotive parts store. Any place like that should have it.

As for the hop up of course, just use 100% silicon oil - never any kind of penetrating oil - as it will literally eat your hop up unit and anything else rubber or plastic.