SONIC. said:
Do you know how to kickstart a bike?
No disrespect meant, it's a learned skill it's not as simple as it looks.
I've kick started many bikes that friends couldn't kick because they didn't know the technique.
Start from the top, start slow then put all of your weight onto the lever, it's not an angry kicking motion with your leg muscles, it's a fluid weight transfer to get some good force behind the kick.
I see so many people kicking the kickstarter like it spit on their mother, that might work on your 125 2 stroke, but it's just not going to cut it on a big 4 stroke.