Ok, this make take some time to explain, but bare with me. I bought a used RM125 that had been "hopped up". I'm fairly new to the technicalities of working on dirt bikes. When I bought the bike it was running, but would not idle, and seemed to bog a little from idle to around 1/4 to half throttle. Upon doing some more research, I discovered it had an old PJ 38mm carb from an earlier year model 250 2 stroke of some kind, and stock carb for that bike is a PWK 36mm. Also it had a 78 slow jet, and a 172 main. Stock for that bike is a 50 slow, and 170 main. It seemed to be running a bit rich. Jet needle is on 3rd clip from the top. It seemed to have good power on the main jet(half throttle and above) once i got there, but it was really horrible below that. Nevertheless, it ran for about a week. I tried adjusting the air screw, but that made no difference, and ended up having it out so far it fell out. I ordered another air screw, and cleaned out the jets and carb. Fired it up, and it idled great on its own for about 30 seconds, and then died. I started it back and had to hold the throttle open a bit to get it to idle, and it was again boggy. I rode it a bit to warm it up, and then I came back to try and adjust the air screw some more, and it would not start again. I then took the carb back apart, and got some smaller slow jets, I now have a 60 slow jet in it. I finally got it to bump start after 3 tries down the hill. It ran great with the smaller jet and was way more responsive from idle to 1/4 to 1/2 throttle, but still would not idle. I parked it to go eat dinner, and came back out to ride again, and it wouldnt start. Pulled it around for 15 minutes with a quad trying to get it to start. It would "ting" like trying to fire, a few times, and even grouped some together like it was ready to rock, but then it would just peter out. Checked the spark plug, and its a little wet, but not terrible. I guess the plug could be in better condition, but it was just running like a champ a few minutes earlier. Also checked the reeds, and they are brand new. Filter is not terrible either. What do you guys think?