At some point over the course of your Tanaka hedge trimmer's life, it is likely to have starting problems. Repairs can involve anything from minor parts replacement to more expensive service. Some of these problems you can fix yourself, but others will require a professional. Knowing the difference may help you save a lot of money.
The spark is delivered up a lead wire to the spark plug. When the spark fires it ignites the fuel inside the cylinder. Dirty, corroded or badly gapped spark plugs are the most common spark problems. When looking for starting problems, start with the spark plug. This will allow you to determine whether you have a spark and whether the spark is being delivered up the wire at the proper moment. If the plug is old, improperly attached to the wire or the wire isn't working properly, no spark will be delivered.
Ignition System Problems
The ignition wire connects to an ignition module, which houses a coil. This coil develops and holds the charge; when the flywheel rotates and its magnets align with the module, the coil discharges the spark up to the wire. Make sure the lead wire is properly connected to the module. Check the magnets on the flywheel to see whether they are discoloured and use a feeler gauge to make sure the air gap is set properly. If the air gap is wrong, the spark will fire but at the wrong time. The starter coil will also begin losing its ability to hold and fire the charge after several seasons.
Fuel Delivery Problems
Fuel flows from the tank to the carburettor, from the carburettor to the cylinder and from the carburettor back to the tank. The engine on a Tanaka requires precise delivery of fuel at the right time. If this delivery system is off or compromised in any way, you'll have starting and running problems. Clean the fuel tank and replace the fuel filter and both the suction and return fuel hoses. If this doesn't solve the problem and you've already ruled out spark, something more serious may be wrong.
Internal Engine Problems
The crankcase and the piston must maintain a consistent pressure for the rest of the engine to operate. Air leaks around the gaskets, seals and crankcase will cause the pressure to drop and the engine to no longer pulse in time with the crankcase. Compression problems can range from a minor air leak to a serious problem in the piston. These problems are best addressed by a professional.