kc laser wont go

[chookaz_351]

Hi all my laser stoped dead on the way to work yesterday and i was wondering if anyone can help me work out whats wrong with it.

While i was driving along the enging just stoped dead and i rolled to a stop ( has half a tank of fuel so its not that). When i turn the key and the starter motor turns the engine it sounds different, sort of whinney.
Now ive checked the vitals, when i twist the throtle fuel squirts into the carby so fuel is getting in. I took out a sparkplug and checked that it still had compression so i dont think i killed it. I also checked that the sparkplug was sparking while it was out and yes it was (although it was more of a yellow spark than a strong blue one. Im out of ideas it just wont kick over.
Does anyone have any idea what is going on? Im desperate i haveto get it going again to get to work. Any help or ideas would be greatly appreciated