I have a problem with my 2003 hero majestic panther. When i get past 25 mph there seems to be a noise in my engine(im thinking it is my piston) and whenever i go full speed (when it gets up to max) the noise gets louder like a siren like noise.. and im thinking it is my piston/piston ring... and another thing is whenever i let off the gas when im about to stop, around 25 mph it does the same thing when speeding up to 25 mph... which is kind of weird.
Another thing is when my moped is just sitting on the kickstand after i start it up/when i stop at a stopsign/when im about to shut it off it has like this clacky noise, like something is hitting something inside the engine(sort of like something is loose i think). My friends dad thought it might be piston slap.. but it seems to get worse every week ... What should i do?!?