Hey, for some reason my CBR250 MC22 stalled out of nowhere, it was working perfectly before and now it wont start. Before this I replaced the spark plugs, took apart the carby and cleaned em all up and was running fine after it was all put back togther, then suddnely as i mentioned above it stalled out of nowhere and wouldnt start up again. my dad reckons its the timing thats gone off and i agree but what else could it be? and if it is the timing how do i fix it ??? cheers!