Be sure to measure the piston width at the skirt and the cylinder width across the area where the skirt rubs. Compare against the specs for your piston (is it stock?) and cylinder. Unfortunately I don't have any specs for you. Anyway, if the piston is lose, especially if the skirts or cylinder are worn, it can rock and make some noise. It could be normal noise, I have no experience with that motor so I don't have any idea what noises it makes.