Another prob with the engin rebuild!!!

K I just rebuilt my little 2000 RM80 and it was a B*%#$ to start. I broke in the piston by taking 2 easy 20 min rides and a little 3 ride to make sure. I let the bike cool between rides but after the 4th time i tried to go more than half throtel but it would just start bogging. Then i took it for a longer ride, well my freind did and after about a half hour we shut it off. It didnt start back up again and we even tried bumb startin it. When we came close to starting it would just backfire. Idk I might need a new spark plug so i'll try one but the plug sparks. Have any other suggestions why this might be happining?

ya the plug was wet, It seems to be flooding easily and a ton of gas flowing out of the carb.

thanks for the advice, i'll try to replace or adjust them