How to Repair a Motorcycle Starter Motor

A motorcycle in an empty room.

The motorcycle starter motor often presents problems after the first year or so. These can be observed in the form of stalling, sputtering noises, and delayed startup. Learning to fix basic problems with the motorcycle starter motor helps in general maintenance and upkeep and is a handy skill.

The electrical starter used in a motorcycle engine is a DC motor that contains two or more field coils known as pole coils. These pole coils are fixed towards the inside of the external starter shell, also known as the yoke. In some motorcycles the pole coils are replaced by magnets since energizing the field coils causes them to act as magnets. The pole core or armature is the internal shaft of the starter. A number of wire coils are a part of the pole armature and every coil leads to a commutator. The commutators have bits of carbon and wires pressed into them. The carbon pieces are known as brushes and the wires within the brushes are joined to the main battery cable. When power is supplied to the cable, these brushes transfer electrical current to the commutator of the armature.

Step 1 - Check the Battery

When the bike doesn’t start properly, the most common source of problems is the battery. If the battery hasn’t been charged completely or is in a poor condition, it is likely to cause problems. Check the battery for damage. If it is in good condition the next step is to check the solenoid.

Step 2 - Check the Solenoid

If the solenoid makes an odd clicking noise, it is possibly corroded and causing start-up problems. One of the ways to check the solenoid is to join a thick jumper cable from the battery to the starter. If there is no reaction this indicates the starter has probably died out. If the starter responds when you charge the two main terminals but the solenoid doesn’t click into place, the problem usually lies with solenoid.

Step 3 - Ensure Starter is Functional

It is also possible that the starter button has become worn out or that the wire that connects to button might have come apart in places. Starters also have fuses which need to be checked. If these fuses blow no electricity an flow to starter, so check the fuses.

Step 4 - Check for Wiring Problems

One of the most common causes of problems in the starter is the occurrence of wrongly connected wires. As unlikely as it may sound, the chances of sending in your bike for repairs and the mechanic mistakenly connecting the wrong wires are actually very high. Many times wires come undone during other repairs and are pushed haphazardly back into place. Seemingly silly mistakes such as these can cost you a lot in the long run if they are not detected immediately. Learn how each wire should be placed and then ensure that all the wires in the starter and the engine are joined at their corresponding terminals. The merest tightening and securing of a wire can make a great deal of difference in the bike’s performance.