'83 GPz 750 carbuetor jet parts

Hello!
Recently picked up a '83 GPZ 750 A1. Bike does not run, got it from a friend who had it for years. First order of business is completely strip down the carbs and clean. I will be using an ultrasonic cleaner among other things. I have on order K&L carb kits #18-2902. The last rebuild kit put in i'm suspect is of poor quality based on looking at the machining and number stamping of jet size. I'm almost 100% certain the bike has other than stock needle jets and the K&L kits don't come with those. Looking at the Hanynes  manual that came with the bike, It says needle jets are Y-8. Kawasaki part # 16017-1138. I see there are different types of Y-8 jets. Does anyone happen to know the correct stock needle jet as it may cross reference over to either K&L or Keyster (or Mikuni for that matter but trying to save $). This bike has a 4 into 1 exhaust, not sure of the make. It also has crappy pods that I will be removing. I have a stock airbox on the way. Current jetting is 37.5 pilot and 130 main I believe. Exhaust will be staying, but I believe (after researching in the forum) that 130 will be too large so I will need a new main jet because i'm guessing the kit will come with a #110 and that will probably be too small. I think I can use the 37.5 pilot that should come in the kit. I will be ordering an Oring kit that I see Nessim has available (is that Z1 enterprise?), new carb to head rubbers, vacuum caps etc. Will perform sync and float / fuel level as well.
One of the things I like to use to clear small passages are  3D printing tip cleaners. Like this kit for example, it has .2mm - .6mm needles. The are very small in diameter, sharp pointed and made of spring steel unlike regular carb cleaning tool.
 

From continued searching, it looks like i'm trying to figure out the Mikuni "series" of needle Y8 needle jet used.
Thanks
Pete

Not sure if this will be of help or not, but here is a table from an FSM for 82 GPz 750 that shows internals for the carb.

the Y9 needle jet would, as I understand it, have and inside diam of 3.145 mm

If you use the stock airbox, the only jetting change you will need to do is bump the main a size, and maybe lift the needle.  I'd start with just the main and go from there.

If you want an O-ring kit, please message one of the mods and they will hook us up via email.  

Thanks for the replies, I'll send a message. gd4now, appreciate the info. I'm pretty sure the '83 is different, but i'd run into the same problem with the Y9. Not much from Mikuni comes up for the Y8 and since I don't have the stock carb "brass" I can't get any meaningful info on the ones I have. I'm finding out alot of searching for Mikuni BS 34 brings up the Yamaha stuff or  VM carbs from Mikuni instead.

Had an email into Mike at Jets R Us and he is not sure what jet I would need. Hoping someone might have one laying around that could get the info directly off the jet.

The needle jet Y8 as I understand it would indicate an internal diam of 3.140mm

Needle jets are available not only in types, but by series and size. Mikuni series numbers for style of the needle jet. This series includes not only the physical fitment dimensions but also the nozzle profile, and the atomization pattern. The sizes (inside diameter size) within each series are listed according to a letter-number combination. The letter shows the inside diameter size in increments of .005mm. See the Mikuni Needle Jet Sizing Chart below for a better understanding


Mikuni Needle Jet Orifice Diameters in mm 
  -0     -1    -2    -3    -4   -5     -6    -7    -8    -9 
N 2.550 2.555 2.560 2.565 2.570 2.575 2.580 2.585 2.590 2.595 
O 2.600 2.605 2.610 2.615 2.620 2.625 2.630 2.635 2.640 2.645 
P 2.650 2.655 2.660 2.665 2.670 2.675 2.680 2.685 2.690 2.695 
Q 2.700 2.705 2.710 2.715 2.720 2.725 2.730 2.735 2.740 2.745 
R 2.750 2.755 2.760 2.765 2.770 2.775 2.780 2.785 2.790 2.795 
S 2.800 2.805 2.810 2.815 2.820 2.825 2.830 2.835 2.840 2.845 
Y 3.100 3.105 3.110 3.115 3.120 3.125 3.130 3.135 3.140 3.145 
Z 3.150 3.155 3.160 3.165 3.170 3.175 3.180 3.185 3.190 3.195 
AA 3.200 3.205 3.210 3.215 3.220 3.225 3.230 3.235 3.240 3.245 
BB 3.250 3.255 3.260 3.265 3.270 3.275 3.280 3.285 3.290 3.295 
CC 3.300 3.305 3.310 3.315 3.320 3.325 3.330 3.335 3.340 3.345 


 

thats great info, thank you. I was just able to deduce a jet listed for this bike, but had "Z2" as the last two would then not be correct. 

What do the needles look like?  The stock needles are anodized aluminum.  Most aftermarket needles are raw brass.

OK it appears that you are wanting to find/discover the series of needle jet in the Y8 size for the Mikuni BS 34 carbs that came stock on the 1983 GPz 750 also known as a ZX750-A1. I do not know the answer to that question off the top of my head, but will do some more research for this info.  As you pointed out much of the info one can find on Mikuni needle jets is related to those used on VM type of carbs and not much on BS type carbs. 
 

Guys! I took some steel wool to the outside of my jets and low and behold they are stock Mikuni's! I apologize for jumping the gun and asking for so much help when it turns out I should have cleaned and looked closer first. Lesson learned.The stock needle jet is # 430-Y8

Glad to hear it.  If the jet needle is the stock one it should also have an ID (num) on it as well.