Just got a 72' AT2 in trade that looked okay but has been a complete turd so far. After a bunch of work I got it running and it smoked like Cheech & Chong. Not a little, like fill the room smoking. I'm still fairly new to working on bikes, only been wrenching seriously for less than a year. My guess is crank seal. I attempted the first start without exhaust and only got it to pop and backfire a couple times. Then put a brand n.o.s. race pipe on I had in my stash. After the smoke session I removed the pipe and oil ran out of it. From reading, guessing right side seal?? I pulled the clutch cover after draining and did see some seeping from seal but nothing extremely obvious like it blown out. Am I headed in the right direction? I have yet to pull the clutch basket as I didn't have my impact handy and wanted some advice first.

If bike has been sitting it might just be loaded up with autolube oil.

Over a few years oil in tank tends to leak into and fill crankcase with oil... very common in my experience.

I would take it out for a good run before tearing it apart. Accumulated fuel and or oil in the crankcase will produce a smoke machine. A good run should clear this out. If that doesn’t work maybe you need to attack the seals. Good luck with your project..

Okay good to hear. My other ? and essential piece for running it enough to clear out is the slide doesn't slide in the carb. Seems stupid but I can see how the PO struggled to get the frozen slide out with a flathead. I swapped the slide from an AT1 carb thinking they're both vm24 and it does the same. Maybe sand down lightly the inner carb? There's the cutout for the idle speed screw and the thinner cutout adjacent to it for that little notch maybe that little notch got boogered up. After taking the clutch cover off I wiggled the kicker spline and accidentally pulled it out ao I'll have to upload a pic tomorrow and make sure I get that right. Thx all

Is/was the slide in backwards? ie, was the cutaway facing the rear, the air intake? Sometimes PO's get that backwards, and that might have something to do with it. The grove in the slide must mate up with the little nub in the cylinder (of the carb) wall. Duh? Right? But some guys (PO's) have a hard time with that...

I checked the slide, I think they just marred up the inside of the carb enough to make it not slide smoothly. Think I'm just gonna put my other AT1 carb on for now and sort it out. I think I got the kicker spline back in correctly, see pic. The red lines arr where I aligned things and attached spring. When I move the spline slightly as if kicking it seems to engage properly. Fingers crossed I can start it later, smoke clears and I get an early xmas gift.