Ryobi RY34001 Operator's Manual - Page 12

MAINTENANCE SPARK PLUG REPLACEMENT This engine uses a Champion RY4C spark plug with .025 in. electrode gap. Use an exact replacement and replace ­annually. CHANGING ENGINE LUBRICANT See Figure 12. For best performance, engine lubricant should be changed after every 25 hours of operation. To change the engine lubricant:  Stop the engine and disconnect the spark plug wire. Allow the engine to cool completely before proceeding.  Remove the screw from the top engine cover and set aside.  Remove the screws from the bottom of the engine cover. Remove the bottom cover and set aside.  Remove the oil fill cap/dipstick.  Tip power head on its side and allow lubricant to drain from the oil fill hole into an approved container. NOTE: Drain the lubricant while the engine is still warm but not hot. Warm lubricant will drain quickly and more completely.  Return the power head to an upright position and refill with lubricant following the instructions in the Adding/Checking Engine Lubricant section previously in this manual.  Reinstall the bottom engine cover. Replace the screws and tighten securely.  Replace the screw in the top engine cover and tighten ­securely. NOTE: Used lubricant should be disposed of at an ­approved disposal site. See your local retailer for more information. ADJUSTING CAMSHAFT-TO-ROCKER ARM ­CLEARANCE See Figures 13 - 15. Inspect the camshaft-to-rocker arm clearance after every 25 hours of operation. This should be done in a clean, dustfree environment. NOTE: This procedure requires partial disassembly of the engine. If you are unsure if you are qualified to perform this operation, take the unit to an authorized service center.  Stop the engine and disconnect the spark plug wire. Allow the engine to cool completely before proceeding.  Remove the screw from the top engine cover. Remove engine cover and set aside.  Using a Torx screwdriver, remove the screw from the rocker arm cover. Remove the cover and set aside.  Position camshaft by pulling the recoil starter grip just until the deep hole in the camshaft gear is located at the 6 o'clock position as shown.  Place the feeler gauge under each rocker arm and measure the gap. The gap should be between .006 in. (0.15 mm) and .008 in. (0.20 mm) for both rocker arms. NOTE: Use a standard automotive feeler gauge. The .006 in. (0.15 mm) feeler gauge should slide between the rocker arm and valve stem with a slight amount of resistance but without binding. The 0.008 in. (0.20 mm) feeler gage should not slide between the rocker arms and the cam lobes - it should be held tight.  If the valve clearance is not between .006 in. (0.15 mm) and .008 in. (0.20 mm), the clearance should be adjusted as follows: • While holding a wrench on the flats of the adjusting nut with one hand, loosen the retaining nut with a second wrench as shown. Take care not to loosen the stud. • Rotate the adjusting nut until it touches the feeler gauge. Once the gap setting is correct, hold the wrench on the flats of the adjusting nut and retighten the retaining nut securely.  Adjust the second rocker arm, if necessary.  Replace the rocker arm cover and screw; tighten s­ ecurely.  Replace the top engine cover and screw; tighten ­securely. WARNING: Ensure all engine cover and all engine parts are completely and properly reassembled before starting engine. Failure to correctly reassemble engine may result in serious injury or property damage. STORING THE PRODUCT  Clean all foreign material from the product. Store idle unit indoors in a dry, well-ventilated area that is inaccessible to children. Keep away from corrosive agents such as garden chemicals and de-icing salts.  Abide by all ISO and local regulations for the safe storage and handling of gasoline. When storing 1 month or longer:  Drain all fuel from tank into a container approved for gasoline. Run engine until it stops. HIGH ALTITUDE ENGINE OPERATION Please have an authorized service center adjust this engine if it is to be run above 2000 feet. Failure to do so may result in poor engine performance, spark plug fouling, hard starting, and increased emissions. Carburetor adjustment by an authorized service center will improve performance and allow that this engine meets EPA (Environmental Protection Agency) and California ARB (Air Resources Board) emission standards. An engine adjusted for high altitudes can not be run at 2000 feet or lower. In doing so, the engine will overheat and cause serious engine damage. Please have an authorized service center restore high altitude modified engines to the original factory specification before operating below 2000 feet. 10 - English