Going on what you've so far described I would look for play at the big end of the crank. It sounds like you're finding bits of needle bearing from the big end. Anything else (rings, roller cage etc) tends to go in a big way and you'd notice - because it would stop dead. If the big end wobbles front -to back - it's time to get a new crank. Good luck -
OK, You are looking for any signs of 'pitting' or 'craters' in the top of the piston or the inside of the cylinder head. If you see marks like metal has been 'picked' out of the surface, then there's a detonation issue and that could be ignition timing or fuel mixture. If the piston is badly blackened or discoloured as if it's been overheated, then this isn't a good sign. Overheating could also cause the needle bearings in the small end of the crank (inside the piston) to start to fail and this might be a source of the metal 'bit' you saw. You also need to look for any signs of scoring on the inside of the barrel, by carefully turning the engine over by gently moving the kickstart by hand. DON'T use the enectric starter, but if your bike doesn't have a kickstart you may need to remove the transmission cover to be able to turn the variator by hand. Let's see what tomorrow brings before jumping to conclusions. Keep your camera handy!
Nothing wrong I checked everything I even toke it to UFO motorcycles they said nothings wrong. They dose my mixture screw after they done that I only get white smoke on start up
