My 125cc Chinese scooter doesn't start with the electric start button. However, when I short the two starter solenoid poles together, the scooter starts fine. I replaced the solenoid itself, but the problem persists. So I assume there is something wrong with either the electric start switch or brake sensors.

I do not have the time to diagnose and work on it at the moment. So I plan to connect a simple button to the solenoid, which will short the two poles when pressed. Is this safe? I will probably use the solenoid bypass button to start the bike for at least 6 months. Will doing this frequently damage anything in the scooter?

Secondly, I would appreciate if someone could give me ideas on how I could connect the button efficiently, and also the type of button to be used.

Any advice would be highly appreciate.

Thanks a bunch

3 Answers 3


Your best bet is to get a simple automotive relay and attach it to the scooter, with the relay providing the power to the solenoid and a momentary switch (what you called a "button" switch) to energize the solenoid. The momentary switch won't have the ability over time to support supplying electricity to the solenoid to energize it, so you'd end up having to replace it at some point (maybe even more than once) during the six month period.

As for whether this will hurt the scooter, I would doubt it. You are only replacing what the factory is doing.

My only thought is, if you are going to take the time to put something like this on, why not just fix the scooter in the first place. It probably wouldn't take any more time than what it will take to affix the relay and momentary switch.

  • Thanks for the answer. What's the purpose of the relay in this case? Can't I just connect the momentary switch to the solenoid, which will short the two poles when pressed?
    – Jspake
    Commented Mar 19, 2017 at 14:17
  • Diagnosing the problem is what will consume time. Unless you can generously share some ideas of how I can diagnose the problem, starting with the most likely issues? That would be appreciated :)
    – Jspake
    Commented Mar 19, 2017 at 14:19
  • I already explained the purpose of the relay is to prevent the momentary switch from burning out due to overload trying to energize the solenoid. If there is a relay already in the mix, it could be that, or it could be the switch. Really, diagnosing the problem would take you just a few minutes. Commented Mar 19, 2017 at 16:03
  • Aha. And is the relay usually located in the starter solenoid package? This is exactly how my starter solenoid looks: ae01.alicdn.com/kf/HTB1yk72LXXXXXbpXFXXq6xXFXXXe/… Sorry for being a nuisance, I am a novice at all this
    – Jspake
    Commented Mar 19, 2017 at 17:03
  • The solenoid is a relay of sorts in and of itself. It provides for the high amperage load which occurs when you push the battery current through to the starter. A relay as I'm suggesting would be connected to the momentary starter switch which you usually use to start the scooter (if it even has a separate one). Putting a relay in as a temp solution may be overkill, but it will work without issue. Commented Mar 19, 2017 at 17:55

If your solenoid has more than 3 wires (batt, starter, key), then when the solenoid is energised it could / should also provide a feed to the coil (probably) and if this is not working the that may be why you have difficulty starting.

  • I replaced the solenoid with a new one. The scooter still doesn't want to start. Any ideas of what else could be going wrong?
    – Jspake
    Commented Mar 19, 2017 at 16:35
  • Does the wire going to the solenoid go live when you push the button? If not, then you have to track back (or forward from the starter button if you prefer) to find the culprit. Does it have a switch to prevent staring in gear for example. That is the logical step to find the fault - that's the fun with electricity...
    – Solar Mike
    Commented Mar 19, 2017 at 16:39
  • Makes a lot of sense. How do I check if the wire going to the solenoid goes live? There is always 12V between the two poles of the solenoid. Sorry, I am a novice at all this.
    – Jspake
    Commented Mar 19, 2017 at 17:00
  • Use a test lamp or voltmeter - connect one end (volt or multimeter the black one) to earth or ground and the red or other end use to test for voltage.
    – Solar Mike
    Commented Mar 19, 2017 at 18:26

I sure hope you've got this worked out by now, for those coming here in search of answers #1 make CERTAIN YOU HAVE A FULL BATTERY AND ALL OF YOUR CONNECTIONS ARE CLEAN AND TIGHT! Ok, sorry about yelling..... If the scooter makes an awful nails on the chalkboard sound along with the obligatory clicking and whirring sound, it is your starter clutch ( behind the flywheel and stator, inside the crankcase.) If if doea absolutley nothing it is either your safety switch on the brakes, the ignition switch, or the start switxh itself. Use a meter to test for conductivity through the switches in startup cindition. You can also snip the black and gray wire coming out of the CDI in wire #6 location. Doing this will bypass the kill switch

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