i was rididng my bike out on the flats and had it pined for .5mi then lost power. and the engine sounded louder. well got home and found the screen in the frame plugged with this lint stuff. looks like dryer lint soaked in oil. took it to yamaha dealer. and asked have you guys seen this and what is it. well, long storie. bike ran out of oil, valves got loud. so yamaha factory was called and they approved 2hrs of tear down and inspect time. nothing was found to be wrong. dealer changed the oil and the filter cleaned screen. so took the bike home and rode two 3hour rides . valves getting noisy again. so i pulled the screen out of the frame and it is plugged again. took it back to dealer and said you told me nothing is wrong. what is coming apart inside my bike. they said that there is nothing in there that would make this. so now i have done 1 110mile race and 1 2hour ride and the valves are noisy again. i am going to pull out the screen in the frame again. see what i find. looking for info.