I looked at it, and the decided not to.
Ever since opening perfectly functioning flashlights to take a peek constantly requires re-modding and waiting a month or two for parts to get it to work again.
Any more info?
Lens diameter?(would AR glass for hd2010 fit?)
Approx. driver diameter 17,20mm?
Is side switch illuminated?
well… woke up this morning and saw this questions, decided to help fellow BLF.
spoken like a true flashaholic, without washing my face or brushing my teeth yet nor have any breakfast.
I decided to open up a perfectly working Yezl Y3 and share the info.
the lens is 56.8mm ( I thought the bezel is glued… but it’s not ) the LED MCPB is the same size as Smallsun TY-08 25mm
the driver size is 23 mm and the switch is not lighted
now while everything is open, suddenly I have the urge to modify this driver and see if I can get a little oomph.
either my brain didn’t function well before breakfast or I’m just a Noob, so I didn’t measure the current before attempting to modify this driver.
so I opened up the bezel to unsolder the wires from LEDs, then by accident I realized… crap I could have just open it from the pill section as the light came in 4 sections 
while I was trying to get the LED insulation gasket off, somehow I managed to scratch the dome grr… :_(
oh well… dedome LED it is, put it on the bench vise and heat it up from under and voila… the dome is off in less than 10 secs 
so I added R200 on top the R180 thinking maybe I should just go easy first and wait until somebody who have more $$ and more crazier than me and willing to sacrifice a perfectly working light :bigsmile:
but of course I didn’t want to stop there… my hand is still itching to solder some more, so I decided to cut the small torroid and replace them with a bigger one courtesy of my busted AK47 9 LEDs driver( BTW I don’t have any clue what does the toroid do in the flashlight, I thought bigger is better :D)
Yezl3 is on the left and AK 47 is on the right
I also changed the wire to AWG 22 and slightly longer, just in case I want to change the resistor, I didn’t have to unsolder the wires again from the LEDs… unfortunately that didn’t work out, there’s just not enough room especially with the new bigger torroid :~
put everything back together and eagerly took out my FandyFire 2010 and put them side by side and…
for a good 30 seconds I was so happy… the hotspot definitely is more intense than Fandyfire 2010 a lot more actually
too bad my crappy point and shoot camera couldn’t capture what the eyes see in person.
but wait… is it because the dedome LED or the resistor mod and torroid mod?
and suddenly the light start to flicker… huh? and it went dim so quickly, I tried to use the switch button on the side to change the mode.
um… nothing happened… say what?!? this light became 1 mode only?!?
turn it off, and switch to another battery and hoping maybe that’s because the battery ( I have doubt it though)
same thing happen it was very bright for few secs and then flicker and goes dim quickly BUT strange thing happen, now the light able to switch mode… huh? what did just happen and how?
it’s perfectly working fine in medium and low mode but not high…
EDIT: now the light is doing all kind of weird things on me… now the high is OK but the MID and LOW is flickering
EDIT again: never mind… now the light only goes in 1 mode… and it’s as in LOW mode ( probably even lower than the original )
it’s driving me crazy now… :Sp
oh well… I think I’m going to have my breakfast now and then maybe after a nap I’ll mess around with it again or maybe I’ll wait until people with more knowledge with sense resistor will start chiming in on this driver 
I just ordered the one with the extension tubes. Saved $3.68 using coupon code LEDWALLBUYS14.
You have to chose “buy it now”, then exit out of the pop up for payment, then go into your shopping cart and enter the code.
I think I’ll leave my driver all stock :bigsmile:
The Tooth Fairy's revenge.
Note to self: Don't mod before brushing teeth.
for me its a good flashlight i love it .
on the site the driver 2.6 Amp but with full pan 3400 its much brighter the spil than one c8 thagsfire direkt drive
Is this with 3 cells? So less than 1A at the tail on high?
ugh… my Yezl Y3 is dead now :_(
Yes. Pretty much stable across 1~3 cells if you use good discharge capability cells.
Live and learn, right?
Alas, poor Yezl! I knew him, Horatio.
OMG, got my Yezl today, so I'm Yezling, like a happy Yezler.
Initial impression is it sure if a fine looking light and has many of the attributes I'm looking for:
- side e-switch with tail switch
- true SS bezel
- takes 26650 cells (would be better if it took 32650's, but still not bad)
- if it performs as good as talked about here, it's a sure bet to be a HD2010 killer in almost every way
- tailstands
I'm getting excited bout this one. I see lots of modding potential here. To me it's just a host, but close to perfect for this form factor. Mod ideas:
- replace tail switch with a tactical switch, and combined with a custom e-switch driver, when the tactical comes on, it will be in full power, then the side e-switch will take over with full ON/OFF control across 4 to 6 modes
- XM-L2 U2 1A on a SinkPAD of course, maybe de-domed - first want to measure throw to see how it really performs
- plan would be to use a Nanjg/Qlite driver (one FET), or customized Z8 base Tivo532 combo FET/7135 driver. Definitely have the Werner/JohnnyC style mode switching: one click to low, one long click to high, one click to OFF once mode is set. So, the e-switch has complete control of the light, and the tail switch is simply a "lock-out" with a tactical high feature
- AR lens swap, if possible, plus all the usual tweaks: copper braided springs, heavy quality wires DeOxit Gold on all contact surfaces, etc.
- review for possible fitting of copper for additional heat sinking - I know it's gonna need it
I'll post stock amp, lumens, throw measurements shortly, maybe some pics. Mine came with the bezel o-ring pinched out, so gotta fix that first. This one will stay single cell only - only way to get the mode selection I want. I should be able to tell soon if the 17mm driver will fit and work out ok.
Please Note: mine came with a 18650 sleeve, the thin see-thru type with the ridge lines on the inside.
Tom - what are the lux and lumen figures for the standard Yezl - and what are they with the sleeve in and running an 18650 rather than the 26650?
Ok, here's some results ....
Tailcap amp measurements (using 14 gauge high qual custom leads):
TrustFire 26650: 2.45A
KK ICR 4200: 2.51A
SONY 50A 26650: 2.52A
Efest 25A 18650: 2.51A
Samsung 20R: 2.50A
Powerizer: 2.50A
Amp measurements are pretty tightly grouped, so suspect it's fairly well regulated to 2.45-2.50 amps. Most of these cells are pretty hot cells, so there is definite amp limits in this driver.
Using the KK ICR 4200 for output measurements, Yezl Y3, XM-L2 T6:
lumens: 901 @start, 874 @30 secs, throw (from 5m): 62.6 kcd
Reference stock HD2010 TangsFire w/TF 26650, XML T6, measured 3.6A tail:
lumens: 908 @start, 898 @30 secs, throw (from 5m): 57 kcd
Certainly the HD2010 at the higher amps performs pretty good, but the Yezel still beats it in throw. The throw to lumens ratio goes to the Yezl, but of course it has the XM-L2 vs. XML, so it's different, but I don't think it has an impact on throw. My for-the-moment conclusion is the Yezl is the better thrower, probably attributable to the reflector, but by a small margin.
You cannot overlook the results here... A totally stock light doing 62.5 kcd on one cell at regulated amps of 2.5 is doing pretty good.
Beam Patterns
No pics yet, but compared side by side to the HD 2010, patterns are very similar - bright intense spot, surrounding flood zone. The spill zone is slightly smaller on the Yezl, to be expected because it appears to have the deeper reflector. Also the hot spot is ever so slightly smaller than the HD2010's, indoors that is.
There's a ringiness to the Yezl's beam, not in the HD2010's, both around the hot spot and at the outer edge of the spill. The HD2010 has the flower shape halo, but transitions are smooth. On the Yezl, the flower shape is not as defined - it's more round, but the ringiness is there.
Now about beams... This is with these 2 units I have here. There could or may be variations piece to piece about how the bezel and o-ring fit/mounted, how the reflector sits on the LED, etc. Also the Yezl appears to have an alignment piece that could block output, while the HD2010 has a pretty thin edged, low profile alignment piece - I won't know for sure until I dis-assemble it. Also, I could have caused the ringiness when I loosened the bezel to fix the bumped out o-ring. I had to use a strap wrench to loosen the bezel, but then I hand tightened it afterwards. To me, this level of ringiness is not so bad, definitely acceptable. I've seen much worse.
mudgripz - re-tested lumens with a Panasonic PF 18650 and get 901-867 lumens -- nearly identical as would be expected for an amp regulated driver.
Lens - definitely glass, size: 56.8mm x 2.04 mm
HD 2010 lens as comparison, size: 58 mm x 2.04 mm
Reflector - aluminum, size: 57 mm OD, 54 mm ID, 41mm depth
HD 2010 reflector as comparison, size: 57.75 mm OD, 51.5 mm ID, 38 mm depth
Hope this answered some questions. I'd say Joe was pretty dead-on with this light. His results of course may be different in what he saw, depending on the cells and amps being delivered in both the Yezl and HD2010 he used as a reference, specially the unregulated HD2010 that varies wildly depending on the cell used.
Yikes, I think I killed Joe's thread! Maybe post #77 was little too much?
I tried a resistor mod similar to what DayLighter did - calculated it to 4.8A, but so no improvement with one cell. On two cells though, I got like 3.5A at the batteries (??), so I'm thinking the bank of resistors only kicks in when the driver is bucking down voltage? Weird... At this point, I'll abandon this idea and go with an e-switch version of a Nanjg, maybe single FET ala comfy.
LOL… 4.8A for single LED is not enough for you Tom? 
Sorry - didn't make it clear -- the resistor mod did not work at all for a one cell configuration - still got 2.4A or so. Tried couple of other resistor mods to other resistors (higher values found on the board) using 50% value resistors, still, no improvement. Ugh - this driver is beyond me... Better for me to go with a custom FET Nanjg driver because it should get over 6A. Thinking this host can handle the heat well. The pill top is pretty thick and where the pill threads in to the front bezel, there's pretty good thickness of metal to get to the cooling fins.
Only bad thing is the lens is an odd size but thinking I can sand down a UCL/p lens to make it fit -- never worked on a UCL/p, so have to find out if it's do-able.
I’m pretty excited for this light. I imagine I’ll be happy with a well regulated and bright stock light for about a week or so before I have to either make it a hot rod or break it completely.
Tom- please keep us updated with your progress with the FET based driver. I’ve never messed with an electronic switch before, so I’d love to see how the masters do it.
Edit- Can you use a FET driver with multiple cells, or will you have to run only one cell?
Ok, will do - I got the driver built, not tested yet, waiting on the JB Weld to dry that's used to secure the FET.
I programmed my custom e-switch driver on it already. Time to bench test...
- This will be limited to one cell unfortunately because it's a simple Nanjg/FET based driver. Could do a Zener mod though, run 2 cells, driving an MT-G2.
Since I’m planning on using multiple cells, I might try to use the resistor mod to bump up the current. You said that that resistor bank only seemed to be in use when there are multiple cells, correct? If so, perfect! What resistor did you use to get 3.5a or with multiple cells?
Also, how easy is it to get to the LED? Was the head glued? Thanks!
No glue on the head, but used one strap wrench -- maybe you could use a jar opener pad...
The 3.5A at the tail with 2 cells is 7A to the LED, so, the resistor I used was a bit overboard. Think I piggybacked an R100 on to the existing resistors -- pretty sure there were 2 resistors in parallel, both under 1 ohm, so easy to spot. Probably need to use an R150 or R200 -- something higher to make the bump lower.