Cylinder and carb issues

[UnclePennybags]

Hi,
I recently bought a new 66cc China motor for my bike, it had lots of trouble starting and frequently died. The carb throttle needle had lots of black gunk on it and the cylinder looks terrible. Bellow are images attached. Can someone please help me fix this or do I need a new top end.

 

[Squiddley]

The gunk could be coming from the gas tank,something to look for,the cylinder looks ok to me but it hard to tell on pictures.

 

[Chainlube]

Take the petcock off the tank and rinse the tank out with some clean fuel, dump out the tank into a white plastic container to see what comes out easily. Take your carb apart and clean it out as well. You can follow along on the carb thread here.

Carby - NT Carb Tuning Basics

A few basics on the Happytime NT Carburetor:- Some pics identifying the basic parts:- Float Bowl Gasket Also see srdavo's NT Carburetor Assembly Pics for a bit more info. Brief Description Of Operation The NT side-draught carburetor operates by drawing air into the air...

motoredbikes.com

 

[Chainlube]

Make sure you have a fuel filter installed between the tank and carb when you're done cleaning.

 

[UnclePennybags]

I already cleaned out the carb but I haven't cleaned out the tank, I have a fuel filter installed. When I try to start it after cleaning it instantly starts for a few seconds then dies and won't start again. I'll clean out the tank and try.