Hi lads new here anyway I'm picking up a custom dtr 125 tommorw will be my first 2 stroke after haveing a few shitty cheap Chinese bikes anyway the guy says it's bogging out because it needs re jetting to the new exhaust it has got a tzr micron pipe it currently has a 240 jet but bogging out at around 55 and not getting and higher speed out of it than that what jet size should I try? Thanks

Hi boyle " downsize the main, to get peak performance, but not too small, get a couple of smaller [ 220/205 . ] do short full throttle runs

then shut of engine and check plug colour,

whats colour is it the now,

And what air filter is on it,

Have a read of other DTR threads

Heres one