can someone please try this (with a GOOD MOTOR) if your head is off the motor turn the crank and explain the movement of your pistons. My crank doesnt move 360* it turns about 1/2 turn and the front and rear piston dont move as quickly as the middle ones (sorry i dont know the order of them)

PLEASE SOMEONE....i just bought this piece of shiotttt!!!! i have never worked on one of these motors b4. Anyone please help.