Bolens 643B, 643C, 645A Engine Cleaning AIR Cleaner Service Engine OIL Service, Spark Plug Service

Replacement Belt Information

If the drive belt needs to be replaced, see your local authorized dealer or refer to the Parts List for ordering information. Use only a factory-authorized belt as an “over-the-counter” belt may not perform satisfactorily. The procedure requires average mechanical ability and commonly available tools.

ENGINE CLEANING

Keeping the engine clean will help to ensure smooth operation and prevent damage from overheating. Refer to the Engine Owner’s Manual for engine cleaning service intervals and instructions. Be sure that the muffler is cool before servicing the engine.

AIR CLEANER SERVICE

The air cleaner filters dirt and dust out of the air before it enters the carburetor. Operating the engine with a dirty, clogged air filter can cause poor performance and damage to the engine. Never operate the engine without the air cleaner installed. Inspect and service the air cleaner more often if operating in very dusty or dirty conditions. Refer to the engine Owner’s Manual for air cleaner service intervals and instructions.

ENGINE OIL SERVICE

Check the engine oil level before each use and after every five hours of continuous operation. Running the engine when it is low on oil will quickly ruin the engine.

It is recommended that you change the motor oil after every 10 hours of operation and even sooner when operating in extremely dirty or dusty conditions. Refer to the Engine Owner’s Manual for detailed service instructions.

A. To Check the Engine Oil Level:

1.Park the tiller on a level area and shut off the engine.

2.Level the engine (use the Depth Regulator Lever to adjust the engine angle).

3.Clean around the oil dipstick or oil fill tube (which- ever applies) to prevent dirt from falling into the crankcase.

4.On engines with an oil fill tube, remove the fill cap and add oil (if required) until it reaches the top of the fill tube. Reinstall the fill cap.

5.On engines with a dipstick, remove it and wipe it clean. Reinsert the dipstick, tighten it securely, and remove it. Add oil as needed to bring the level up to the FULL mark. Wipe dipstick clean each time oil level is checked. Do not overfill. Tighten dipstick securely.

B. To Change the Engine Oil:

Change the engine oil as instructed in the Engine Owner’s Manual.

SPARK PLUG SERVICE

Inspect and clean or replace the spark plug after every 100 operating hours or annually. Refer to the Engine Owner’s Manual for spark plug service instructions.

In some areas, local law requires using resistor spark plugs to suppress ignition signals. If the engine was originally equipped with a resistor spark plug, use the same type for replacement.

SPARK ARRESTER SCREEN SERVICE

If the engine muffler is equipped with a spark arrester screen, remove and clean it according to the service intervals and instructions in the Engine Owner’s Manual.

THROTTLE LEVER ADJUSTMENT

If the engine does not respond to various throttle lever settings, refer to the Engine Owner’s Manual for service information or contact your local authorized engine dealer.

CARBURETOR/GOVERNOR CONTROL ADJUSTMENTS

The carburetor was adjusted at the factory for best operating speed. Refer to the Engine Owner’s Manual for any adjustment information or see your authorized engine dealer.

The governor controls the maximum safe operating speed and protects the engine and all moving parts from damage caused by overspeeding. Do not tamper with the engine governor settings.

OFF-SEASON STORAGE

When the tiller won’t be used for an extended period, prepare it for storage as follows:

1.Clean the tiller and engine.

2.Do routine tiller lubrication and check for loose parts and hardware.

3.Protect the engine and perform recommended engine maintenance by following the storage instructions found in the

Engine Owner’s Manual. Be sure to protect the fuel lines, carburetor and fuel tank from gum deposits by removing fuel or by treating fuel with a fuel stabilizer (follow engine manufacturer’s recommendations).

4.Store unit in a clean, dry area.

5.Never store the tiller with fuel in the fuel tank in an enclosed area where gas fumes could reach an open flame or spark, or where ignition sources are present (space heaters, hot water heaters, furnaces, etc.).

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Maintenance

WARNING

Loading and unload- ing the tiller into a vehicle is potentially hazardous and we don’t recommend doing so unless absolutely necessary, as this could result in personal injury or property damage. However, if you must load or unload the tiller, follow the guidelines given next.

Operators shall not tamper with the engine governor set- tings on the machine; the governor controls the maximum safe operating speed to protect the engine and all moving parts from damage caused by overspeed. Autho- rized service shall be sought if a problem exists.

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