Yamaha Aerox problems starting!!?

[Jethro]

My Yamaha Aerox is a real pain to start! The things ive done to resolve this matter is clean the carb, change the spark plug and buy a new battery. None of this has worked! the only way to start it is to jump start it with my car. Can anyone help?

 

[billZ]

may have crank seals going out or gaskets or piston rings going bad