alright so i picked up a 2000 xr50 for 400 bucks off craigslist. it has a bbr 88 kit in it. so after a while of riding it sounded like my valves were tinging. i adjusted it no prob. then just tonight out of no where they starting tinging like crazy loud. so i pull the fly wheel cover off, get the 2 valve covers off. and when i turn the fly wheel, just when the exhaust(bottom) valve pulls in, where it comes it there is like a ting, like a nail on sheet metal. not i tryed loosing up the valve totally so there is a ton of space, and it does it quietly and anyhwere from like half way tight, to all the way against the valve it makes this noice. im pretty sure its not piston slap as it does it on the exhaust valve. is my cam messed up where it hits the valve? also, when i kick start the bike sometimes it doesnt kick over the motor. are the gears on the kick start stripped? it makes a winding noise.