I just bought an 05 Scorpa SY175F that has the bored out TTR125 Yam engine, no e-start, and magura hydro clutch. It is in very good shape and well maintained, original trials tires still like new. Yesterday the kickstarter kicked back hard against my boot, then a strange knock,rub,peck noise. It speeds up with engine and slows down at idle. Its not in rythym with the engine, but slower like a geartooth on a very large gear every revolution. It does it in neutral, riding slow, with or without clutch pulled in, in gear or out. I pulled the clutch cover and clutch, closely inspected the starter idle gear and the big gear behind clutch basket and all other visible gears. nothing visual could be found. Found a few very small metal chips in the oil screen. Used a magnet thru the holes inside the transmission. No chips. Checked the timing chain and upper sprocket, looks normal. The little bike runs great, no smoke. The noise sounds like inside transmission or behind clutch.Lower end in other words. Anybody know what this could be? I really was not planning to split the case on my newfound treasure the first week!