I just broke in my engine today on my slayer pro 4x4. I did not tune it yet because i did not have my tools. But after the break in i was driveing in straight lines holding full throttl and the engine saounded like it was at max rpm but never heard it shift to 2nd. i am not sure how to tell if it is shifting or not. And i dont really know how to make it shift. I know on my jato 3.3 it shifts fine and i can actually hear it shift, but not on my slayer.