Gas leak/Carb take apart

First question if I take the carb off to look at needles,jets, floats should I buy new gaskets to put the carb back together?

I have a puddle of gas in the morning under the bike the other day it was oil then one day none... Petcock is in the on position. It may look like it is comming from under the carbs on somes posts that stick out the bottom? When I bought the bike someone said it was jetted to big, but everything is stock on it so I don' get that. Stock should be around 102?? All I know is that the carbs say Mikuni also MIC Kogyo. So I think it is really a float problem which could also be my 2 cool running exhaust out of 4/wet dirty plugs on 2 right...


1980-KZ650 LTD

If they are the original paper gaskets on the float bowls then yes, replace them. Why chance creating more leaks by re-using 26 year old paper gaskets when you can get a new set of them on eBay or from Z1 Enterprises.com for about $10~$12.

Jet size shouldn't cause the carbs to leak while your bike is just sitting there and not running.
The "posts" on the bottom of the bowls are drain tubes. And if you unscrew the drain screw located where that tube protrudes from the bottom of the bowl it will drain the float bowls. It's a good idea to have hoses running from those tubes towards the bottom of the bike to prevent any fuel from pooling on top of the engine should they leak, like what is happening on your bike right now.

Normally I would say that if one or more carbs is leaking while not running, that there is something preventing the float needles from seating and blocking the fuel flow, and/or that the tips on the float needle themselves are worn and not seating fully.
But since you say that it appears that the fuel is leaking from the float bowl drain tubes, then the o-rings on the drain screws might be worn, or the drain screw(s) might simply be loose.

From what it shows in the parts listing on the Kawasaki website, the main jet is offered in a few different sizes:
92.5R, #A95, #A97.5R, #A100 and #A105R.
IIRC, the R denotes "for racing use".
I believe that either the #A95 or #A100 would be stock. It usually deonotes on the website what the difference in jet sizes are attributated to, but normally which size would depend on whether you have a California model KZ (which I believe are usually jetted leaner to comply with higher emissions regulations) or a 49 state/non-US model.