About 18 months ago I reported on the on the instillation of a Ross piston http://advrider.com/forums/showpost.php?p=17340346&postcount=11442 Well on mothers day near the top of Ebbetts pass, one of the best motorcycle roads I have ever been on. I Highly recommend this road if your in the area. http://scenic4.org/ The XR started bogging our of the corners, I kept on riding thinking of the high density altitude was the cause , I reached the peak of the pass 8,700 ft and warm out, I started down hill and all was good on the way once I reached 3000 ft and still had the bogg on acceleration I pulled over to try to adjust the mixture, and it died as soon as I let off the gas oil was leaking out of the air box profusely well a long story shortened. the piston cracked Well the ross piston made it near 14,000 miles and made the XR rev easier than the stock piston but I don't think I will buy another one. Looks like i am going With JE on the next overhaul Light weight is good til it is int and this is the case of too light.