my older brother recently purchased a 98 yz400. Yesterday i inspected the valves to be on the safe side. The valves needed to be adjusted so i a began disassembling the motor. I began removing the two caps on the flywheel cover to position the motor at top dead center. When i removed the caps motor oil started pouring from the lower opening. The motor runs fine and there is no apparent problem with the performance. When i adjusted the vavles on my '99 i didn't have oil dripping from these openings. If anybody has any info that would help me out it would be appreciated.