Motorcycle Repair: Carb leaking, honda z50r, air leaks

Question
I have a 93 Honda Z50R that I just recently got a new 88cc big bore kit for it. I got a new carb with it to. The first time I started it it sounded like it when up to full throttle. so I cut it off. and it was leaking gas out of the overflow. I put the fuel line into the right spot this time and it did it again so I left it alone. two days later I took the carb off to see if it was the float. I saw that when the float goes down the needle thing does come all the way down with the float. so I put it back on and started it and it started right up. so I reved it and then it started increasing in throttle again. I tried the idol screw but it doesn't seam to do any thing.

http://cgi.ebay.com/ebaymotors/Honda-88cc-Big-Bore-Kit-CRF50-XR50-crf-xr-z-50-70...  

that is the kit I bought

Answer
Derek,

-the needle valve in the carb needs to shut
off the gas flow as the float bowl fills
up.
-This carb is called a "Shenway" 20mm
and I have no specs for it.
-If your carb overflows fuel you may need to
bend the arm on the float so it
shuts the valve off a little sooner.
-The carb bowl needs to be fairly full
but not running over into the engine.
-Check if your throttle slide is lined
up with the pin in the carb and the cut
away part on the bottom of the slide
is facing the rear of the bike.
-Make sure your throttle cable has a little
slack in it as well.
-Finally, check around your new intake and carb
for air leaks, these parts have to be sealed
against any air getting in or it leans
out the fuel mixture causing the bike to
rev too high.
Try some gasket sealer if necessary.