1981-1984 Official Honda ATC250R Shop Manual, Page 250Get this manual
'83 ATC250R ADDENDUM
Connect the hose to the damper unit but do not tighten yetVery slowly push the damper rod in until ATF begins to overflow from the reservoir hose
Connect the reservoir to the hose with two sealing washers and the oil hose bolt without losing oilDo not tighten the bolt yetAgain, slowly compress the shock until small amount of ATF overflows from the hose joint to ensure that both the reservoir and hose are filled with ATF