Vitos pistons are good pistons, but be careful if you are running a long rod setup! I ran these in my banshee, along with a 4mill long rod and space plate and stock pipes (Yes stock pipes) and plus 4 on the timing I noticed a huge power difference I went from 200 mains to 270 and its did not seem to be running rich at all! My banshee was a total sleeper I would consistently win races with piped banshees, that was the good. The bad was my motor only made it about five hours. the pistons held up just fine until they broke off the rod. My crank had maybe 40 hours or less on it, and the general theory is that the combination of the extra weight of the piston and the long rod may have had something to do with it. that being said, maybe I had a weak rod or maybe it had a crack in that I did not see when i rebuilt it. I am not entirely blaming the pistons I am just putting the warning out there. I would have never thought that the little bit of extra weight would make a difference but my buddy who is a 2 stroke engineer seems to think that had a lot to do with it. The piston rod could have broke for a number of reason but it does seem a little weird that I got 40 hours of reliable operation out of the crank then five hours with vitos piston the rod broke .