my new TMX alpha has an annoying rattling sound when revved to more than 40 km/hr. After consulting Guanzon (Bantay, Ilocos Sur), they had it tuned-up by adjusting the valve (tope) a little tighter; the rattling sound got milder but the noise is quite loud and annoying when i rev it to 50 km/hr. The mechanic said he will tune it up again when the mileage reaches 500 km. Please help. Any comment or suggestion? Thanks, fellas.