1985-1987 Honda TRX 250 Fourtrax 250 Service Manual, Page 26Get this manual
MAINTENANCE
BREATHER TUBE
Remove the plug from the drain tube to empty any depositsInstall the drain plug
NOTE Service more frequentlv when ri ding in rain or at full throt tle, or if he deposit level can be seen in he ransparent section of he drain tube
VALVE CLEARANCE
Inspect and adjust valve clearance while he engine is cold
(below 35 C95 F)
Remove the timing hole cap and rotor ca pRemove the fue tank (page 4-3)
l oosen the ai cleaner case-to-frame connecting ube bands (page 4-41 and slide the connecting tube so that he rear valve
adjusting hole cover can be removed Remove the valve adjust ing hole coversRotate the crankshaft clockwise and align the "T" mark on the rotor with he in dex markThe piston must be at TDC on the compression stroke