Sitting Duck

if he ever has a cardiac arrest they would need to hook him to National Grid as he has zapped himself soooo much a reg defibrillator would do fuck all to him unlike this guy...

I'd like to say I have nearly mastered soldering mostly from studying this electronic legend... taught me everything I know (next to fuck all)

like many things - the more you practice etc... but soldering/teching - basically anything like this is like riding a bike - not so much you don't forget it but more learning to ride a bike for first time you can read all this crap & watch all the YT clips but in the end you gotta just have a go and pedal like fuck as you wibble wobble your way through life figuring shit out hopefully not falling arse over tit too often armed with a little idea of what to do then it's a matter of keeping at it I guess

Diode is easy on a cheap std motor with tabs at sides it is other motor types like G&G/SHS you might need to careful of std Cyma motors have tabs at sides - so a schottky diode is no biggy but yup - what until stuff breaks or really need to open her up = wise decision

plug n play mosfets do not protect the trigger contacts from arcing Avacado, Burst Wizard are two of the older plug n play mosfets (need a fucking mensa test to get ya around programming the sods though) but did not protect trigger contacts in plug n play mode the Burst Wizard could be used as plug/play and also hard wired in by adding the signal wire THEN it protected the contacts properly depends on what you after fancy feature bollox or contact protection... https://www.airsoftworld.net/airsoft-gun-spare-parts/aeg-spares/internal-parts-1/mosfets the £11 perun will suffice for basic mosfet - but it is FUCKING TINY or for cheap make-do contact protection you could just add a diode to reduce the spark from EMF inductive load from motor the big fuck off spark like a spark plug isn't when the contact is made but mostly when the switch opens again and the massive spike appears as the switch opens - from the energy/zap from motor (really freaky scientific/physics shit we didn't take note of at school) or you can call it a fancy fucking name SLE bollox Switch Life Extender - cheeky bastids it's a diode ffs

don't we all ???

I did wonder why say AB for a modest gun when we know they sometimes stop 99% precocked on mild speeds or COL still partially raised basically it's a cheap but half decent gun - just don't go tooo nutz on it I love cheap shit - even if it is a bit qwirky (like moi) well no - I'm just fucking weird than just a little qwirky

nanoasr - the non-AB fet don't think you want AB (straight swap for warfet if wanted) x-asr or a cheap perun basic fet be best option perhaps can afford to leave it in there for low price option totally agree good eyepro & boots with support (especially for kids - whatever the size, even the really big older ones)

an old review of a 515... now a bit of a heads up of what might be in 516... https://translate.google.co.uk/translate?hl=en&sl=fr&u=http://www.france-airsoft.fr/forum/index.php%3Fshowtopic%3D198758&prev=search could be clear old stuff or blue tappet plates etc... think I got a distant French relative coz he goes into mega detail on it can be a bitch to remove on some Cyma's them two lugs really make it harder to get out them 2 little lugs - jeez they make it very hard to easily remove - really don't need them to be that difficult

The 516 won't be a Quick Change spring so opening it up requires a tiny bit more care due to spring still inside as said you could swap barrel/hop combo around as they seem similar lengths of about 300-ish to check if messed up & focus on one gun than screw two guns up at once Warfet ain't cheap on 516 £70 gun it's up to owner but a basic mosfet will suffice and even then a schottky diode will reduce sparks at trigger contacts deans connectors are probably worth a go £ for £ if you can solder but this crap is for another day get one gun sorted first then with wisdom/experience look at any issues/upgrades on other perhaps again - remember even with a £150 Titan it is still a £70 Starter

Well as explained (briefly - *sarcasm) the KIT offers excellent value - nuff said but as explained the nozzle may wobble the piston "might" bind (it might not) the cylinder only available in full or half type (as said you got the correct cylinder in there about 3/4 though at times the type in fractions or type A-B-C-D is a bit vague I prefer to measure the distance of port to front say 43mm) The piston head is alloy - but a good type for compression yet some prefer lighter and possible less risk of scratching POM piston head (I've always said give same gun to say 10 techs and they will all have their preferences of what to change, what keep etc... how far to take stuff on what budget etc...) waffling again The kit offers very good value - don't think anybody can deny that (price it up separately & see for yourself) The issue is one or two components might not be best suited as is for the Cyma v2 (nozzle is one example, it might fit OK but RA is oem SHS so reckon it will be a little loose) Don't get me wrong - you could buy just the basic Cyma piston & new o-ring AND the KIT for a future gun or if the other gun went tits up and you was fine doing some minor checking/minor modding to ensure it went together OK I'm just pointing out the options and the value in the kit (get full cylinder perhaps & you can make it ported if you wished to your spec) I'm not saying deffo get the kit - I don't know what your budget of toy gun shit is (especially in January after Chrimbo cleared you out) If funds are tight just get the piston & o-ring if you're OK or had money to splash then get kit as well PERHAPS Now at risk of pissing Pete off - he's gonna fucking kill me you could ask Pete via pm/facebook or whatever to measure the piston between the rails to check dimensions and see if it is much thicker than Cyma or a bit thinner than SHS pistons that often bind in some boxes (that way you might know if it will bind or just need a light sand to glide smoothly) it's not just between the rails, but the rails themselves how much they protrude but some pistons bind a bit & some bind a lot that effects its efficiency (even risks PME) SHS pistons I have are 19mm between rails (a smidge under/over at either end) Cyma metal rack pistons are say 18.15mm aprox with the pinky ones being 18.4mm to 18.55mm say (so as said they sit inbetween SHS & Cyma pistons) I dunno what Pete's XT or even ZCI pistons are but highlighting why some pistons bind in some boxes etc... The XT piston could be fine, not as fat as bindy SHS I really don't know - but SHS can bind in Cyma/JG's and Cyma pistons can be a little wobbly in say a G&G box for my liking as said this "Tokyo Marui Compatible" is more like compatible-ish at the best of times yeah might need a "slight" mod there m8 I mean for starters to see if I'm talking out my arse a sec you can grab some plumber's ptfe tape wrap around 7 wraps around the cylinder head and retest to check seal (it is a BODGE, but does work if done neatly - trim off excess with scalpel etc...) the o-ring, you can remove and wrap it around the outside of cylinder to stretch it (some warm the rubber, some leave it on cylinder for weekend/week to naturally stretch a little) but a new better fitting o-ring is best as the Cyma one is a bit small to begin with do that crap - test compression, see if it improves for next to nothing heck you can test for leaks at cylinder head in a bowl/sink of water looking for puncture (nozzles will never seal 101% as they gotta move freely so will blow slightly under pressure even with an o-ring or double o-ring or they struggle to glide free & smoothly) see if that improves compression but you will need a new or stretched o-ring at least to check compression (coz the std one is a bit shit) and the cylinder head OMG Cyma it is as loose as fuck - plenty ptfe required but can do the trick on budget without buying numerous bits that you don't REALLY need to (Just Cyma - the fucking head is a bit too loose compared to some makes) You can get by with mostly stock stuff and get these to sing quite well (like Luke at NA does so often) I've covered the extra work regarding SHS nozzle & tappet plate in Cyma's I normally use plastic cylinder heads if I can get them to seal well others will replace with alloy head etc... then some nozzles are a too tight fit on some spouts or vice versa so then I might change stuff around or go to plan B etc... again waffling & over thinking shit, but I got a box of bits n bobs spares to swap shit around I'm giving you the heads up, what options there are and offering you the simple straight forward approach plus mindful of not buying more stuff than is really necessary to get it going too As said, not wishing to piss Pete off (much) but say if he popped the XT piston in say a JG v3, Cyma v3 if he hasn't a Cyma v2 shell to hand (that's another fucking annoying thing about Cyma v2's, they got a smaller cylinder window that a bare piston won't fit through on its own like most v2's to test if a piston might bind) if the piston doesn't bind in a JG/Cyma v3 box then chances are it "shouldn't" bind in Cyma v2 if that be the case you could buy the kit and use most of it - nozzle might not wobble (but think it might) but use most bits - though get a couple of o-rings - one for the other gun at some point As for the other gun - if it shoots OK then LEAVE IT ALONE you could swap barrel/hop/bucking combo over to test/try if they are similar length but I'd avoid stripping down both or fucking around too much - always leave one gun working (plus if it ain't broke (or not too bad) then don't try to fix it)

Glad you got stuff ordered to help with ya 621... I could have suggested the "compression kit" Pete @ak2m4 does... https://www.ak2m4.co.uk/m4-compression-upgrade-kit Which offers great value at say £5 each piston, piston head, nozzle, cylinder, cylinder head However not sure the ZCI piston binds a bit like SHS in some boxes (Cyma certainly wont) The SHS/RA nozzle is loose on the qwirky Cyma tappet plate - well SHS is for certain Cylinder head would be nice but 7 wraps of ptfe will improve the shit loose std one Cylinder - well the Cyma ones are usually a decent silvery type with port suited for gun already (crappy brass cylinders are OK, but snappy guns they tend to warm up a bit if people start to polish these brass ones a bit inside you can feel how quick they warm up) Piston head - well if you put on a better o-ring that is usually all it will need (after ptfe cyl hd) and like I said sometimes you change more bits you can run into issues (especially on the slightly qwirky Cyma v2 boxes) So just replace & service what you need to get ya going again With regards to jamming - could be number of things decent bb's really make a difference, G&G's though expensive are a good brand sold by many places cheap eggy ones with seems & variations in manufacturing result in all sorts of issues even weight fluctuations on cheap batches = bigger fluctuations at chrono too G&G is just a well known, easily available brand at many shops/sites some rate Geoffs or Blasters - just use something "decent" if you can You could be trying to hop stuff too much, trying to lift .25's on some shit bucking winding the hop on more & more on a hard/crappy bucking until it just cloggs an old stiff bucking struggles to control finely the backspin/lift on certain BB's like tight bucking lips - the BB is wedged either under nub or in case of tight bucking lips the BB is stuck just outside the bucking both will clog up the flow of compression & risk PME The trick is to NOT KEEP FIRING - especially on Auto remove mag, fire a few shots on semi - if no joy then likely use jamming rod etc... misfeeding - actual MISS feeding is another issue that "usually" doesn't jam ergh it misfeeds - though a jam will cause other rounds to misfeed of course different mags can feed better/worse sometimes they can pull/push hop unit slightly which can effect the nozzle clearance to chamber a BB up feed tube into hop unit & through lips into position under nub People think mid-caps MUST feed better than a high cap not always the case, some midcaps the bb's can snag inside the mag's long snakey spring that pushes up 120 or so bb's without winding - trust me some mid caps are shit for jamming (sometimes at anytime, usually as the follower turns tightly in one of the bends inside mag) A good high cap should feed say 20~25 BB's without winding (once fully wound) don't leave a high cap wound or spring tension goes shit & only feeds say a dozen bb's or less You may find that some guns like a certain mag - this is not uncommon your 621 might be more picky than the other M4 and one or two mags work better/worse Feed issues can be tricky to diagnose (especially via forum text) so experiment and diagnose through a process of elimination to reduce potential jams in each gun sometimes you can fit a delay clip to assist feeding/chambering of bb's but on Cyma gears - there is a bigger cam on sector that most delay clips won't fit on so looking at changing gear/sector to fit a delay clip to improve nozzle/tappet retraction... naahh - not yet perhaps (something to look at at a much later date down the line - just get gun working again) Jams could likely be hop on too much with an old stiff shit bucking and/or shit bb's in a dirty barrel, which the 6xx series is supposed to a tighter barrel so give barrels a good clean too and use decent bb's Tight Bore Barrels need to be kept clean and any minor irregular shaped bb will not glide down it Got a 600mm shitty MadBull TBB barrel that is tighter than a nun's whatsit and very few bb's can drop through that easily without snagging - way too long and too tight So shit like 6.01's are just too tight - especially in longer barrels 6.03 barrels are about as tight most people generally use with quality BB's (but still need a bit of reg cleaning) Try different stuff, on say 7.4v LiPo to establish what BB's & mag work best for each gun then go a bit nutz once you know it feeds reliably etc... They're s/hand guns (I think), so expect the odd niggle heck we still get minor niggles with new guns, like new cars/bikes etc... You'll suss it all out in the end I'm sure for trouble free peew peew peew

Gotta laugh at the desperation in the MSM Reuters/BBC desperately trying to find shit to post regarding armed protests The odd genuine middle aged person might have turned up (unarmed) on their own But the rest look like soy drinking hipsters carrying Cymas to me... I mean look for yourself: https://www.reuters.com/news/picture/us-capitals-see-few-protesters-after-bra-idUSRTX8N0Y3 https://www.bbc.co.uk/news/election-us-2020-55699533 but think MSM are desperately scrambling to find some to run with (even if most of what they managed to push seem to be soy boys that popped into Evike than actual proud boys that stocked up at say Hyatt gun stores etc...) UK society today...

Can't accuse me of composing very brief & vague posts just bored shitless & very very very sad

Oh leave off - I'm still trying to figure that out myself

Kids not going back to school ??? it happens during July~August no offence to younger players out there but just shedding some light out there to possible reasons - Detective Inspector Duck

Didn't win anything - just guesswork but we've all broke shit lots of times in many different ways THIS is my favourite of favourite pic that sums up diagnosing shitty bastid toy gun issues.... poor OP won a fucked piston & lost his posting ability whilst having to wade through all my crap instead - ouch that's gotta hurt

Seems like the hop might have caused a BB to jam than actual speed which resulted im PME piston shredding he can't post atm so is posting in updates bit maybe lips or hop on way too much - well what ever Another piston to be careful is the 3 & 7 tooth dark grey ones from TWG they are a bit shit also had one just rip the rip initial pickup tooth right out https://www.taiwangun.com/piston/reinforced-piston-with-seven-steel-teeth?from=listing&campaign-id=19 Hard as fuck - like nails that plastic, like brittle hard as fuck plastic had some 3 & 7 tooth versions... I think the pick up tooth is way too large/deep and kicks the sector as it returns had one of those just crack the pickup right out was a long time ago - but knowing what I know now I could carefully file the massive pickup down a smidge and keep checking shit in top half of box as I often do yet my gut feeling is just a tad ultra hard & brittle plastic/polymer but another piston I tried and thought nah fuck it I got a few pink OEM ACM 7 tooth pistons - they're fucking ace as well as some pink full metal rack pistons about 3 years ago from GF for a few quid - they were fucking awesome & didn't bind in boxes like SHS did wish I could find them but reckon they are long gone from production would be like finding a fixed stubby M4 stock - like rocking horse shit or hens teeth nah - tried 3 part metal/plastic pistons and only one of them was any good and that one is no longer in production it seems - just my luck so tend to stick with metal racks myself - but to each their own here are the OEM ACM pistons that I love... the 50/50 rack is at back - shiny surface but these are damn good pistons - that don't bind like SHS's need a bit of work/cleaning up but fits the bill when a SHS binds if anybody sees these around they are pretty good pistons imho (probably seen them in some of my build posts) I'll use a SHS metal rack in a G&G as it don't bind Try a Cyma metal rack in others but if the G&G is too tight, the Cyma is a tad loose (bit too much plat left/right & up/down as piston moves back/forth) Then one of these pistons are usually chosen as they are in between a tight SHS & sometimes smidge too loose Cyma yup they are/were damn good 'uns where as the SHS & TWG grey 50/50 pistons - not such a wise investment Something similar to those pink 50/50 pistons is this... https://www.taiwangun.com/piston/reinforced-piston-with-seven-steel-teeth-bw?from=listing&campaign-id=19 Often I didn't need them or out of stock to add to a previous order BUT if anybody is doing a TWG order at some point & might need a 50/50 piston well I reckon they could be worth a gamble on buying a couple of them That was about the only piston I saw like my 50/50 ones I've used/rated hasn't got the full complete intact rails but nigh on might need to check the initial pick up tooth isn't too high (in some boxes rubbing on sector's toothless area, very fine file) extra material on 2nd/3rd tooth surrounding area - bit of work removing chunky pickup tooth, won't need much to even partial correct AoE etc... (yes often shit needs a bit of tweaking, glue the rack etc...) if it is like my pink ones, they shouldn't bind in most boxes but not too much play/slack either - just the right fit to glide without binding End of the day, it's a case of checking & getting whatever shit you got to hand all operating smoothly & efficiently etc...

@miserydrift has hit his daily post limit it seems so this is why he hasn't responded it seems @Davegolf - yes metal rack pistons give you weak point but the SHS 3 steel & 7 steel pistons are shit imho the plastic is softer not so durable like stock Cyma/JG 1 metal tooth pistons in fact SHS 3 or 7 tooth pistons are weaker than G&G stock pistons I've found the plastic teeth stripped quickly - way too quickly and at mid 20's so not PME plus SHS's - well the metal rack ones may bind in there so expect the 3/7 teeth ones too (no biggy but a bit of modding will fix) however I just think the SHS part metal rack pistons... well the metal teeth are fine it is the plastic teeth is just a bit DairyLea imho weaker than decent stock pistons like Cyma/JG as I said so the OP now might have an understanding on keeping the ROF down a bit so a metal rack will be fine & durable... AS LONG AS THEY DON'T GO NUTZ - which hopefully he understands it a bit better OP might grasp the fact there is no fail-safe or weak point to avoid risking PME if push came to shove I could send him some stock Cyma pistons (hardly been fired), if he was that worried but as long as he understands the limitations/rof stuff he should fine with a robust full metal rack yes maybe part metal rack - but nope not SHS 3 or 7 tooth rack (Sorry SHS but your plastic is way too weak/soft) people can argue or differ in their opinion on these pistons but had one fail very very quickly on me also - remove the 2nd tooth etc.. on a SHS part metal rack - see how easy it is to remove with a sharp knife cor - this is easy... yeah it fucking strips easy too in use then remove a tooth on a hard Cyma/JG piston - not quite so easy coz it's more durable material fucking shame coz SHS pistons are nice n light - just really don't think they are that durable tbh (sorry if people think otherwise - but I gathered up any I had and flogged them on fleabay years ago)

I'm wide awake most times but still veer right off the actual subject so far as I forget what the bloody original question was... sorry what was I saying ??? Ya probably right 11.1v used causing rapid shredding guessing these issues is a fun challenge at best of times I love it when the poster just mentions they was running it on 14.8v LiPo and you then think - oh just fuck off now or - yeah it might be a short as sparks were flying out the back blowing the fuse so I just used silver foil to bypass it - WTF ??? or yeah it did make a big crunch, jammed up but now it is working but nozzle doesn't move much you know the 3 pages in & then you start getting the rest of info how shit broke not directed at OP, has been fairly up front - just sometimes it is a major guessing game THEN the real truth comes out - wtf didn't you say that at beginning ffs !!! Sorry what was question again - I'm waffling again

Them Cyma QC boxes are something else when the piston shits the bed they eject the piston for you nah - get some more kip he said he opened it up to check what was fucked here: click arrowy bit to see the reply... as to why it shit the bed on just 5 rnds on semi ??? dunno if the Cyma bespoke mosfet is an AB type or just a std mosfet - really haven't a fucking clue could be std, could be AB with the extra bit of pcb bollox if AB then it should have made the piston stop on a tanner after cycle & not PME like a std mosfet could but reckon it was a jam on nutty auto burst that likely killed it or seriously injured it at some point (most PME wrecks occur on auto - well mine have when taking the piss & even with planning - still wrecked on auto seeing oooh this goes quick - oh FUCK)

luckily.... he has the QC Cyma box with mosfet in there which helps to open up with spring removed (ahhh the fun explosion I had opening my first SRC box) it is a weird non-reinforced at back Cyma - 13:1's will go straight in (ergh - keep gears as is btw, don't change more than you need to) A SHS piston "might" not bind like the reinforced Cyma boxes (both v2 & the .028 v3's - SHS pistons bind in those) Still just replace with Cyma piston is safe option imho & reassemble Blue tappet is way better than old clear tappet Cylinder head is same floppy fit - only in blue than white Piston head - sometimes a silent mushroom type other times it is same concave piston head now in blue than white (still needs o-ring stretched/changed for compression) Nozzle is same std type non-o-ring but in blue than clear got a 517 in November - blue stuff inside 8mm cross bushings "seem" to be slightly different/revised or new source, tiny bit chunkier, slightly less shimming room than older original 8mm cross bushings I remember box was still reinforced at back, mod req for 13:1's has a ARL window in it now it didn't have before Std trigger switch - OMG this is blue and the shuttle/trolley has loads of lateral play in it, I slightly pinched the contacts straight (less flared) shaped them to touch but not grab the trolley... Fucking thing was moving sideways all over the place missing the contacts at times Don't remember the old white trolley switch as loose as this So changed the switch/trolley due to lots of lateral play in it The sloppy blue switch in the new revised cheap 517/5xx M4's is my only gripe (and still uses the prongs at selector plate) need to often carefully widen the switch mounting "eyelet" if using other v2 switches Still got the silly safety arm to undo prior to opening box But overall pretty robust stuff inside with mostly minor improvements (still crap o-ring & loose as fuck cylinder head) Not a fantastic improvement, nor say another half a point but say an cheap as fuck 8/10 became say a 8.25/10

Cyma's are not turds though (honest) yes they still make low power turds but the 5xx series & the slightly better 6xx series really upped the game for others they are slung together - but they really are pretty decent starters their v3 AK's have much respect etc... even by the high end players their M4's are also very good value - just a tiny little bit qwirky in some areas but all or nearly all gun manufacturers can be a tiny bit qwirky on some models some shit works no problem but there is always the TM compatible myth in fact it is really TM Compatible-ish as often most builds/upgrades need a minor tweak/mod just don't go too nutz and make more work/problems than you need until you gain a bit of experience with these Chinese sweat shop toy guns etc...

Ahh - good stuff the previous owner bought the twin pack nub hard black/soft red you need to check it was fitted OK by plopping a bb into hop unit then it should only need a light moderate push with match/cocktail stick or very carefully a thin screwdriver, just something to pass the bb through lips if it is tight then that will misfeed or mischamber the bb causing misfeed/jams... somewhere in this vid he goes through the "push test" DON'T GO MODDING SHIT !!! it is just to show tight bucking lips causing feed issues tbh just test the lips are not too tight - that's all I doubt if you got tight bucking, but always worth a check coz you will have issues feeding again do not do anything like modding hop etc... just check the lips are not too tight on bb push test - that's all

Could be a genuine failure - the piston head loose (unlikely) rubber pad on cylinder head came adrift (unlikely, but a possible) could be a jammed BB - this will plug the compression and slow piston return tbh - think this is a bit unlikely as Cyma compression as std is not 101% awesome o-ring is meeehhh, cylinder head loose as fuck so not mega insane compression building asap stopping the piston's return like on an awesome setup if s/hand the previous owner could have caned it and risked PME then you got unlucky when you picked it up to put some rounds through it not a massive biggy - it could do with a minor tweak but don't go too nutz it's pretty decent and still a £100 gun no matter what shit you chuck in there just change what you need to improve the meehhh compression - bit of grease and get it going again ptfe will work - but you will need quite a bit of it normally only say 3 wraps - but about 7 on really loose Cyma heads yes you could change cylinder head, but then some cylinder heads are tighter looser "spouts" for certain nozzles etc... Yes you can change nozzles too - but an SHS red M4 nozzle sits very loosely on a Cyma tappet plate and Cyma tappet has cut outs coz it is reinforced inside Sooo to use a Red SHS Nozzle you need a SHS tappet plate & then modded like a Cyma/Lonex tappet with the cut outs up front... See how something "so simple" becomes more & more involved ??? hence sometimes it is wiser to change as little as possible to avoid creating a new issue (or two) for every "improvement" you attempt hence perhaps keep it fairly straight forward for your first attempt as these Cyma's are a tiny bit qwirky - still amazing value just a few things you need to be aware of before chucking money into them most stuff works - but a few things can be qwirky and minor mod/work required plus you change more & more without checking stuff you can create issues or make matters worse if you are not careful At times it is very wise to keep things somewhat simple (especially with cheap chinese sweat sweat shop toy guns assembled by a 5 yr old)