Piston is installed correctly. That 143 piston I refer to as the bisexual 143cc piston due to its ability to work with so many different klx heads. Being it was designed to work with so many different heads the valve pockets look very odd. Your question is a very common question asked. Tb probably gets that question asked once a week if not more. I have done some write ups on some of the fb pages on the matter. The pockets are so grotesquely generous that it doesn't matter if IN is on intake side or exhaust side you still have plenty of depth and radial clearance with valves. I have do NOT recommend flipping it so the IN is on exhaust side. Wrist pin does have about an 0.030" offset. And flipping the IN to the exhaust side would put the offset on the wrong side.