1986-1989 Honda TRX250 FourTrax 250R Service Manual, Page 27Get this manual
MAINTENANCE
DRIVE CHAIN
CHAIN SLACK INSPECTION
Never inspect or lubricate the drive chain while the engine is runningStop the engine and shift the transmission into neutralMeasure the drive chain slack midway between the sprocketsCHAIN SLACK: 30-40 mm (1-141-12 in)
CHAIN SLACK ADJUSTMENT
Loosen the socket bolts: ('86, '87: piecesAfter '87: pieces)Turn the adjuster to decrease or increaseAdjust the chain slackINCREASE: Turn the adjuster clockwise DECREASE: Turn the adjuster counterclockwise NOTE Viewed from left side of sprocket"' "7t
Tighten the socket bolts to the specified torque in 2-3 progressive stepsTORQUE19-23 Nm (1.9 -2.3 kg -m1417 ft-Ibl NOTE If drive chain slack is excessive when the adjuster is moved to the limit of adjustment, the drive chain is worn and must be replacedRecheck the drive chain slack