Why does my dirtbike smoke so much (like clouds of smoke)?

I have a 2003 honda cr85rb. It ran fine before then one day it just lost power. It bogs when i let out the clucth until i get higher rpms and sometimes it won't even let the rpms go up even if i'm not giving it gas it won't go back to idel rpms. I have replaced the bottem end gasket, the top end gasket, the exsaust gasket, and the reed gaskets. I also just put in a new pistion and rings and cleaned the carbarator. The jetting is fine and the float doesn't stick. I've heard it could be a bad crank seal but how would i tell? I was running it a 42:1 and it ran perfect (very little smoke). I've thined my gas out twice to see if that was the problem and its not. The first time I drained my tank and got all new gas and mixed it to 38:1 and still smoked crazy. The second time i drained it again and got all new gas AGAIN (not cheap 5 gallons at a time) this time i have it at 32:1 and it still smokes. So is it a bad crank seal and how would i know for sure if it is? Also is the any other possible reason it could smoke so bad?

First of all, you describe that you add more oil to the gas - why? Shouldnt you add less - like 50:1?

replace the seal - you will know instantly if it was the cause.
Also check if the spark plug gives spark every time, check the seal and gap on it if its correct (replacement is always a good idea).

Sorry my bad. I don't know why i thought i was going down. The first set of gas had 16 oz of royal purple two stroke oil to five gallons of gas(40:1). The second set (also the first time i thined it out) i had 14 oz of two stoke oil to 5 gallons of gas(45:1). And the third time i had between 10-11.5 oz premix oil to 5 gallons of gas(55:1, 60:1, 65:1)