how to get my motor bike going again?

i was out for half a hour on my bike and it started gng slow and whn ya put full rev on it cut out so i cleaned all the carb and where the beilt is there a curcle thing and inside that was 3 clips but when i look they was only 1but should be 3 so i baught 3 new plastic and fited them and the piston and everythng is k put everythng right and back togeather and now it starts but for a couple of seconds and the somke is gary colour thn it cut out and wouldnt start and now whn ya press the eletric start it just makes the clixcking sound and nothing elese and now cant get the bike going