1981-1984 Official Honda ATC250R Shop Manual, Page 28Get this manual
MAINTENANCE
ATe 250R
THREADS
REAR SUSPENSION
SPRING PRELOAD ADJUSTMENT
The rear shock spring preload can be adjusted for the rider's weight and riding conditions1Remove the seatrear fender2Place support under the engine to raise the rear wheels off the ground3Measure the distance between the top of the threads and adjuster lock nutDistance: 10 mm (0.4 in) 4To adjust preload, loosen the lock nut with pin spanner and turn the adjusting nut5Tighten the lock nut and reinstall the seat unitSee section 13 for shock disassemblyADJUSTING NUT