hi sorry for posting this as i know its really simple but i couldnt find it anywhere, standard jet size for 2 stroke 125 runner, i bought it a non runner and fitted another crank and bearings and piston as it was all fried, been using it for work but its pretty sluggish i think its running rich as it goes faster with the airbox off and the plug is pretty black, its got an 86 in there any1 know if this is right or not? oh and its a 20.5mm carb, thanks for any help.
