I just picked up a '98 WR400, it came with extra sprockets and chain. Sprockets are 14/49t The currect rear is 50t and I have taken the front cog gaurd off to see what it is. Whats stock? Also, the bike needed a new plug when I picked it up. It had been sitting for about 3-4 months. New plug, started right up, but the old one was rather foul looking. Is this bike way to rich? I'm ass-uming 4-Strokes dont foul like 2-smokes. Thanks.