I posted on here a while ago that my 74 dt125 was not running right out of nowhere, well I took apart the engine and but it all back together and now it idles and runs BUT it keeps reving up by itself and the idle goes down when I pull the choke out, I’ve had this problem before and it was an air leak but I can’t figure out where it’s coming from this time. I’ve felt around the reeds, carb, and exhaust for air being sucked in and sprayed starting fluid all around the carb,reeds and exhaust but it does nothing, I’m thinking it’s the left side crank seal but I’ve heard that they don’t usually go bad?? And I’ve had trouble getting the armature off, any suggestions on what it could be? I’ve already tried to get the armature off by sticking a bolt in the hole and tightening another bolt on top of it but it ended up bending the smaller bolt and it got stuck inside, thankfully I got it out after a few hours. I don’t want to have to take it off if I don’t have to but I’m not sure where else it could be leaking from.

Firs thing i'd do is back the idle speed screw way out so you can feel or hear the slide touching the bottom. That way it can't rev up except for idle mixture jet fuel which won't go far. Then screw the idle mixture screw in to lightly seat it & leave it there at richest mixture setting. Then start it on choke & flick the choke off then see if you can keep it running & controllable using the throttle. For the armature removal there's a 10mm bolt with a long nose extension that pushes from the bottom of the crank hole. By memory 'without finding mine' the step down is 8mm because also by memory the long bolt that holds it all together is something odd ball like 9mm.