Everyone agrees he is not ready, but why is he taking off the dirty diapers??? My 1st child was potty trained by 2, the last 3 (out of 6) much later!!! Both boys were 4 and my girl was 3, she is the youngest. Some may be due to my lack of consistancy. Too busy homeschooling other kids, etc.
But I wondered if you had tried any rewards? There are cute targets for boys to aim at, fun game! Boys typically pee in the potty 1st and poopy is later. I did a chart with my last and it worked real well. She got a small candy for going and a big smiley face on the chart. She is now 6 and still wears a pull-up at night b/c she sleeps so soundly. If she gives me grief about going the last pee-pee b4 bed, (which she will do maybe once or twice a month) I bet her (a quarter or 2) that she can go, and if she does, she gets the money. Guess what, she tinkles everytime!!! She is very strong willed, but has not figured out I am tricking her. Lots of things can be motivators. You just have to find what works since you don't want poopoos on your floor.
Hope this helped!