4strokes are better for street...
2 strokes need a much richer jetting for street use. with mx- or offroad-jetting on longer high-rpm-distance on street, makes them run to lean and kaboom...
the guy who bought my 2000 gasgas ec300 in 2003, had blown this engine in only a week, on street use only. as he picked up the bike i gave him a list with the right jettings in mx, offroad and street . he ignored that and a few days later i had the engine back on my workbench for a complete and real expensive rebuild . the piston was new with only 3 hours as i sold it... and the idiot had damaged the cylinder so hard, that the welder said : no way! and the engine needed a new one ...