well this spring for my birthday my dad got me a 2010 yz125 and as soon as i got it i put a fatty pipe and powercore 2 silencer on it. i had these people tune it and at the time i thought it was right but later on it would bite me in the ass. My mom lost her job and so we were tight on money and wen i was riding i relized all my power was just.... gone. so my firned took it apart (sence i knew nothing about working on bikes) and the ring over heated and flat sided it and it scratched my cylender so i had to get a whole new top end... not bad right? second ride in IT SHOWS THE SAME SYMPTOMS! and yet again flat sided ring and scratched cylender wall so again a whole new top end kit. my friend tuned it and its running strong and i no this for a fact this time haha and before that ive had carb problems for about a week and couldnt figure it out because i would turn it off and gas would just flow out of the carb. so i checked the float.... not it! so i did it another 3 times praying something would click back into nplace and it would run good but it turns out a seal broke and it was ablke to let gas pour through. then my fork seals broke. if the bike traets me like this again next year im dropping it and getting a diffrent bike but i love two strokes and as long as its leagal im going to own one