I bought a 2013 model SX250 KTM. It was used and about 3 months old when I purchased it. Bought a Vertex piston ( (66.35 mm) to put in it. This is what Vendor showed for a 2012 model. The 2013 models are not offerd yet in catalogue. When I pulled the original piston out of bike it has a Vertex (66.34) stamped on top. I am thinking this is an A piston. Am I making a mistake putting the ( 33.65 in this bike? Is it ok to run the bigger one or am I asking for trouble?