Lost Power MBK Rocket

Hi guys, I have a MBK rocket from 1999 and the bike seems to have no power iv'e played around with the carb but still every time I try to ride when i'm stationary and i twist the throttle it bogs a for about 5 seconds while slowly moving forward then it goes but even when it stops bogging it still has got not a lot of power at all my mates 4 stroke Chinese ped goes faster which doesn't mean anything good HELP!!

 

sounds like the mixture is off, but check compression first and go from there

 

ok will do thanks guys