Im working on a YFZ426 and got a new motor for it, since the crank, head and valves were wasted on the old one from a skipping timing chain. The engine I got used is out of an ATV conversion, put it back into the bike. It had a wetsump conversion so I converted that back by putting the oil pump from the original in the new motor and putting the lines back where they should be including the Y line from the side cover, case and head. The motor starts, runs relatively good but makes alot of racket, almost rattling like a cam chain hitting a cover on down revs mostly but is usually present most of the time. The header pipe is scary hot, to the point its sparking (there is a little rust on the header pipe right outside the cylinder) and the rust is sparking off. I have to check the fuel/air screw but I am worried there is something else going on, do these engines make a fair amount of noise is it common for a rattle hear and there?