I'm running in my 66cc beastie, it's only got 80km on the clock at the moment.
She fires up easily enough using choke, within 2-3 mins runs well with choke off.
Low range pulling is fantastic but when I get the speed up it sounds like it's faultering. Almost like it's only firing every second stroke.
The plug has no residue on it, still shiny silver, running 20:1 mix, blue smoke at mid throttle to WOT.