Grimmreaper09

Hi im seeking advice on my 2015 yamaha mt125 its got just over 4k miles in 8 months, now im looking to see if any1 that owns one themselves has had any engine rattles between 4k-6k revs . Has been getting louder n louder ( yamaha sayed there is nothing wrong a few times ive had it dwn) plus it also needs to be topd up with oil every few weeks or so. No leaks round it wat so ever ( sound like tapids or vavles) im not a mec lol Mods ive only done is a gp mivv exchust and racing chain and sprocket plus tail tidy nothing major Every time i bring it to yamaha i pay for them to look at it and they say theres no probs. This is the prob i had with my last yamaha dt 125 i bought 2nd hand and engine blew so if any one out there can advise me thx