well they did a predator head motor for me that couldn't fall out of a tree. the back yard mechanic of me tore it down and found the valves hitting the pistons and the pistons hitting the head. after alot of help from boat racer I had some one else notch the pistons and cutting them for clearance on the head. put it back together myself and it picked up 6 miles an hour in the 1/8. mike offered for me to send it back but after everything I had been through just to get it hell no they had there chance. I had bought a ton of stuff through them before this.