3. INSPECTION/ADJUSTMENT ATV 300/250 Cylinder Head Cover VALVE CLEARANCE Inspect and adjust valve clearance while the engine is cold (below 35). Remove the cylinder head cover. (See page 7-4) Index Mark "T" Mark Turn the flywheel clockwise so that the "T" mark on the flywheel aligns with the index mark on the right crankcase cover to bring the round hole on the camshaft gear facing up to the top dead center on the compression stroke. Inspect and adjust the valve clearance. Valve Clearance: IN: 0.1 mm (0.004 in) EX: 0.1 mm (0.004 in) Loosen the lock nut and adjust by turning Valve Wrench the adjusting nut Special tool: Tappet adjuster E012 · Check the valve clearance again after the lock nut is tightened. Round Hole CARBURETOR IDLE SPEED · The engine must be warm for accurate idle speed inspection and adjustment. Warm up the engine before this operation. Start the engine and connect a tachometer. Turn the throttle stop screw to obtain the specified idle speed. Idle Speed: ATV 250: 1500100 rpm ATV 300: 1600100rpm When the engine misses or run erratic, Air Screw Throttle Stop Screw adjust the air screw. 3-7