|Tech Tips by Randy Pozzi|
|Tech Tip #36 Honda CH250 Starter Replacement|
Electrical problems are the hardest to diagnose and service because the wiring system is a loop with all the components working in tandem. Throw in an intermittent electrical problem, and it really taxes your ingenuity.
The engine starter system is quite simple. A starter is an electric motor needed to turn over the engine to start it. With the Honda CH 250, when you turn on the ignition switch, depress the rear brake switch then hit the starter switch, a circuit is completed. The positive side of the battery is circuited through the starter relay switch to the starter motor which when energized, cranks the engine.
If you suspect you are having starting problems, first check the battery for freshness and voltage. You can do this in several ways. Easiest is to run a voltmeter across the terminals of the battery. A fully charged battery should be between 13.0—13.2 volts. If you have a charger with a diagnostic interface, connecting the charger to the terminals will determine if the battery is good. I always run a current draw test to see if the battery holds a charge under load.
Next, check the starting circuits. If you turn on the ignition switch, the front headlight should be on and the front turn signals should work. When you depress the rear brake pedal, the rear brake light should be on. This signals that the starting circuits are in order. If you hit the starter switch with the ignition switch on and the engine fails to turn over, you may have a starting system malfunction.
If you have determined that the battery is good, when you try to start the scoot, there should be a clicking sound coming from the starter relay. Remove the frame center cover, depress the rear brake pedal, and turn the brake lock lever to the “lock” position. The relay coil is normal if you hear a click when the starter button is depressed with the ignition switch on. If you do not hear a click, jumper between the posts of the starter relay with the ignition switch on and the starter should turn. If the starter turns, replace the starter relay.
If your battery and starter relay are good and the scoot does not turn over with the jumper between the posts of the relay, you may have a bad ground to the starter, broken positive lead to the starter or maybe just a dead starter that may require just brush replacement.
The easiest way to remove the starter is the following:
YOU DO NOT NEED TO REMOVE THE ENGINE FROM THE FRAME!
Remove the seat, center cover, right and left side covers, left side foot rail and passenger peg, right and left side shocks. Disconnect the starter ground from the frame and the positive lead to the relay.
Raise the engine from the rear tire with wooden supports to its highest point. Remove the two 8mm starter mounting bolts and remove starter.
To bench test the starter, connect 12 volts DC to the positive wire on the starter while grounding the starter frame. The motor should turn. If the starter fails to turn, the most likely culprit is the stator brushes have worn to replacement status. You will have to disassemble the starter motor to be examined or take the starter to an automotive electrical shop for appraisal. Replace starter motor as diagnosed. Reassemble scooter in reverse order as instructed.
The Honda CH 250 uses a 12-volt CCW Mitsuba SM-8 starter. It is a very reliable and durable starter. Usually, if the armature is good, all that is needed are brushes installed to get it working again. Brushes are about $10. The Mitsuba repair kit is about $35.
Randy Pozzi (5/09)
and maintained by doug Elam