I agree with Ronnie, stick with the standard bikes ignition, saves money & if you have all the gubbins should be fairly straight forward to get working ,
Tho I think a Bandit engine in a "Fun Kart" would be wowee scarily quick
, they are not a huge BHP engine ( roughly 60 to 80 ish BHP ) but in a Kart that weighs next to nowt it,ll be warp factor stuff, fun tho
cheers
andy