If your gas-powered scooter isn’t starting using an electric starter, you’re probably desperate to find a solution which doesn’t involve taking your scooter to the shop or making expensive repairs.
In this article, we’ll go over why your scooter might not be starting and give you a few tricks regarding what to do before taking it into the shop.
Understanding The Scooter Components
The scooter’s components have to work together in harmony to both start and then to sustain the starting reaction to run. It’s important that you understand that your scooter’s engine has two different states: successful perpetuating combustion, and being off.
For your scooter to start successfully with an electric starter, your scooter needs to activate the components in the right order after receiving the correct input from you.
Your input is to turn the ignition, to disable the engine kill switch, and to press the starter button.
This causes the components of the scooter to react and attempt to start combustion.
Your actions each affect a different component of the scooter, though.
Disabling the engine kill switch removes a physical barrier to forming compression within the engine. Pressing the starter button completes a circuit between the battery and the spark plug and also a circuit between the battery and the compressor, and turning the ignition opens the fuel valve.
So, to get your scooter to start with an electric starter, the following components need to work in harmony:
- The fuel valve
- The battery
- The spark plug
- The compressor
- The battery
You also need to make sure that the scooter has gas and that the battery isn’t drained, of course. Let’s go into more detail regarding the starting process so that you’ll be able to identify points of failure.
Understanding The Starting Process
The starting process goes something like this:
- The fuel valve opens
- Fuel rushes out of the gas tank into the compressor
- Fuel enters the compressor in each of the engine’s chambers and fills them
- Electricity from the battery powers the starter, which powers the compressor to allow it to begin compressing fuel
- The fuel is compressed by the pistons of the engine, still using battery power
- The spark plug sparks, causing the fuel to explode
- The explosion of the fuel pushes the piston backward
- The force of the piston being pushed backwards powers a resisting sprocket which restores more power to the battery than was used in the first compression
- Fuel floods into the compressor
- The process repeats and the engine is on
Now that we’re familiar with the way that things should work let’s look at where there might be problems that would prevent the process from becoming self-sustaining.
Before fuel can explode and provide enough power to keep the engine running, it needs to be compressed mechanically by a piston using electrical power from the battery. If your engine isn’t starting up but it’s making noises, it isn’t compressing fuel effectively.
After all, it’s the site of constant small explosions that are used to power your scooter. Unfortunately, problems with the compressor tend to be expensive to fix, and there’s little you can do yourself.
If your engine is failing to compress fuel and you are using an electric starter, there will be a few symptoms that might point you in the direction of an electrical failure rather than a true compression failure, though.
If your engine is sputtering but refusing to turn on fully, your battery may be low or dead.
If your battery is low or dead, the pistons can’t compress the fuel enough to create an explosion that generates enough energy to restore enough power to the battery to repeat the process.
Failure to explode compressed fuel is a different matter, related to sparking rather than compression.
If your attempt at starting your scooter is met with only a small amount of sputtering, your spark plug may be the culprit—or your battery. If your spark plug isn’t sparking because it has broken, your engine can’t explode the compressed fuel. Spark plugs are relatively cheap to replace, luckily.
Often there is an even simpler issue, however. Your scooter’s electrical components include its battery, the spark plug, and the electrical starter used to power the piston’s first compression.
Like many electrical systems, your scooter has a set of fuses for each of the components that require electricity. If one of these fuses is tripped or blown for whatever reason, your scooter will behave as though it has a dead battery—you won’t hear any sputtering when you try to start it.
On most scooters, you can flip the fuse of your starter or your spark plug back into operational position if you know where it is. If it’s blown entirely, you’ll need to replace it, which shouldn’t be expensive.
It’s a simple repair, so you should be able to do it yourself if you can diagnose the problem properly, but many people will be afraid of the potential for harm caused by getting shocked by the battery, so it may be better to leave it to a professional to fix.
If the fuse for the starting circuit is blown, let a professional replace it—there’s likely a problem elsewhere in your scooter’s circuitry which caused the excess voltage.
Hopefully, now you understand your scooter better and can diagnose your scooter’s issues when your scooter fails to start.
Johnny C Mitchell says
The electric starter on my 49cc TAOTAO THUNDER WONT WORK it won’t even make a clicking noise but my kick starter works can you help me and give me some tips on how to fix this problem please thank you and God bless you
Hi, my scooter wasn’t starting electrically, on utube i learnt that connecting the starter relays could help. so i short cutted as advised and it started. kick star is doing too. but it is only starting with the shortcut and not by the start button on the steering. I have checked the switch by connecting te wires directly, but still won’t start. i also connected directly the brake wires, still not starting. again it starts only with shorcutting the startyer relais. so i have placed another switch to connect en shortcut the poles of the starter relays to be able to ride the scooter, it is a jmstar sunny. but still i want to know the fault and make it in the original state. please!!
I’ve read somewhere on the internet that if it starts by connecting both poles on the solenoid, that means it is bad and you need to replace it. I’d look into that some more before you replace it though cuz I’m no mechanic.
Hello my moped will not start by the start switch enless I have driven for some time and haven’t left it sitting for more then 30 minutes. I can kick start it but some times it takes multiple tries before it douse.