Gy6 50cc carb rebuild

[chuck123]

Hi,
I am starting my project with a carb rebuild. The carb is a JE15JM1.  I haven't seen the float bowl drain extension it has in any diagrams. Anyone know why one is needed for easy access to drain carb?  
Also, any input on carb rebuild kits and parts that should absolutely be replaced.  It has fuel coming out of the petcock when I apply vacuum and has a spark but no hint of a start. Looks like it's been sitting awhile so I will pull and clean gas tank too.  I just want to make sure it is worth working on. Just a fun project and so far spent $25 for scoot, $20 for battery and $8 for solenoid (I tested old one). Also plan on new rings, piston, etc. Any help there too is appreciated. It is a 1P39QMB so not sure yet if is oversized bore. As I mentioned in a prior post, I have experience many years ago on Vespa P200s but nothing on these.
Thanks in advance for any input,
Chuck

[claydoh]

The extended tube is just for convenience, I think for those who store or don't run it often. Saves having to take the seat and carb off to drain it.

Replacement carbs are inexpensive (<$25 USD), may be worth going that route price-wise over a rebuild kit, or attempting to clean it. If it is the original carb, it probably is sealed, which would require carefully drilling out some screws and a plug to get at the bowl and mixture screw to clean/replace anyway.

[scooter7878]

By the time u buy a rebuild kit and shipping ur almost at price of a new carb and like said sticks are not adjustable without removing the mixture plug and drilling the bowl off and on top that there's no needle clip adjustment if ur just looking to be sure the motor is gonna start spray some carb clean through vacuum port in intake manifold it will run for a few seconds. Than order a new carb for 30 bucks from Amazon or something