so my xr100 burns more oil than an oldchool oil lamp so i pulled it apart and its in pretty bad shape. guess the previous owners neglected the crap out of it. cylinder is pretty chewed up, piston rings leak, valve seals leak, cam journal is chewed to shit. anyways when i got to the head to take the 2 valve seals out, i became dumbfounded when i found only one seal. after i inspected to see if one of the seals just dissapeared and got eaten by the cam sprocket or lifters, i noticed the valve guides are totally different. i have no clue how one seal for 2 valves works. so does the bike really only have one valve seal?