i purchased a used wr426 about 1 year ago. a couple months ago i started hearing weird noises coming from the engine area. i only ride once or twice a month with a fried of mine here in north central florida. the air filter gets cleaned every 2nd or 3rd ride and have changed the oil twice. rite after i heard the engine noise the first time i took it to a local shop and the mechanic said it was probably chain slap i was hearing and that it sounded fine to him. being this my first four stroke dirt bike i said okay. But heres what scares me. The sound is more evident the last few rides especially when lugging (what i call running at low rpm and slowly applying throttle) and possibly more so when warmed up. And when i just changed the oil there was a lot of metal shavings on the filter. a friend of mine said just let it blow and buy a used motor because it would be cheaper. that just doesn't sound right to me. I am fairly mechanically inclined and could pull the motor to inpsect an area if i knew were to start. what should i do? ps i haven't notice any loss of power if that matters.