new problem with moped

[Lou123]

Hi,
My moped recently had trouble starting...
at first i had to use a combination of both using the electric start plus the kick start and once the bike had been used then it started up perfectly everytime after it with the electric start.
When it had been left over night and i came to ride it again it just wouldnt start completely. No matter which method i used.
I stripped it down and checked the carbureter...which was clean
i then checked other things inc. dirty fuel tank aswell...its clean
and the spark plug was working perfectly
i then took the fuel pipe out of the carbureter, blew up it to let the fuel come through and then put it in to the carbureter...
when i started the bike it worked fine with the electric start
After this i decided to also do a different method of starting the bike up whilst the fuel tank was not attatched to anything...then re-attached it to the carbureter and, again, the bike started.
It ran at idle for as long as it wanted
When i gave it a bit of throttle up to 4000 rpm (which is the speed amaount it starts to move at) then it cuts out and i have to start all over again
The moped i have is a CPI GTR 50
does anybody have any suggestions as to why this is happening and anything that can be done to resolve it?
comments appreciated,
Thanks