1983-1985 Original Honda ATC 200X Shop Manual, Page 22Get this manual
MAINTENANCE
VALVE CLEARANCE
NOTE: Inspect and adjust valve clearance while the engine is cold (below 35C95F)Remove the seatrear fenderTurn the fuel valve OFF and disconnect the fuel tubeRemove the fuel tankRemove the crankshaft hole cap and timing mark hole cap
INDEX MARK
TIMING MARK HOLE