sound like its running out of gas, and or the jetting is not right, +1 on getting a plate, pingle, and gutted cap, and you do know why they make the rods longer right, it decresses the thrust pressure at an angle onthe cylinder, making them last longer, your builder didnt accindetly put in the pistons for the 5mm long rods did he, im just asking we all make mistakes, (like getting addicted to these expensive ass things)