Yamaha YZ250FM 2021 Owner's Service Manual

MAINTENANCE INTERVALS3-1EAM20157MAINTENANCE INTERVALSEAM30369MAINTENANCE INTERVALSNOTICEECA25871• After a break-in or before each race, always check the points shown in “TORQUE-CHECKPOINTS” for tightening torques and retighten them.• Periodic inspection is essential in making full use of the machine performance. The life ofparts varies significantly according to the environment in which the machine runs (e.g., rain,dirt, etc.). Therefore, earlier inspection is required by reference to the list below.TIPItems marked with an asterisk should be performed by a Yamaha dealer as they require special tools,data and technical skills.No. Item Routine Afterbreak-inEveryrace(about 2.5hours)Everythird race(about 7.5hours)Everyfifth race(about 12.5hours)Asrequired1 * Valve• Check the valve clearances.  • Check the valve seats and thevalve faces for wear. • Replace. 2 * Valve spring• Check the free length. • Replace. 3 * Valve lifter• Check for scratches and wear. • Replace. 4 * Camshaft• Inspect the camshaft surface.• Inspect the decompression sys-tem.• Replace. 5 * Timing chain• Check for damage and sticking. • Replace the timing chain and tim-ing chain tensioner as a set.  6 * Timing chain ten-sioner• Replace the timing chain and tim-ing chain tensioner as a set.  7 * Camshaft sprocket• Check for wear on the teeth andfor damage. • Replace. 8 * Piston• Inspect crack. • Inspect carbon deposits and elim-inate them. • Replace the piston, piston pin,piston pin clip, and piston ring allas a set. 9 * Piston ring• Check the end gap of the pistonring. • Replace the piston, piston pin,piston pin clip, and piston ring allas a set. 10 * Piston pin• Inspect. • Replace the piston, piston pin,piston pin clip, and piston ring allas a set. 