help with my engine.

[sti831]

hey guys, im new to this site amd i just want to say that i really like the contents of this site, and that all the members seem really helpful. im not sure if i have a 49cc or a 80cc... but when i run it for like around 5 mins, it starts to bog and then it dies. it alsoo starts to feel heavy... any suggestion?

 

[Hot Wheels]

Do you have the right mix of gas and oil ? Or you may need to adjust the screw on the carb and turn it in to lean it out.