So Your 50cc Scooter Won’t Start Has Spark and Fuel But!

Published September 14, 2023 | By Gotscooters

So Your 50cc Scooter That Won’t Start

Hey there! So, you’ve got yourself a shiny 50cc scooter, and it’s a blast to ride. But one day, you try to start it, and it refuses to budge. It’s frustrating, I know, but don’t worry! We’re going to tackle this issue together, You’ve got spark and you’ve got fuel now we’re going to figure out why it’s not starting. When it comes to 50cc gas scooters, there are versions the pull start and the electric start. The pull start version, as its name implies, requires you to pull the cord to initiate the engine. Conversely, the electric start version offers the convenience of effortlessly commencing your scooter with a mere button press, prioritizing user-friendliness and ease. Each version boasts its distinct advantages, enabling you to make an informed choice aligned with your specific needs and preferences.

Why Spark and Fuel Aren’t Enough

You might think that having spark and fuel should be enough to fire up your scooter, But it’s not always that simple some times, it’s the little things that can cause a big headache.

You’ll Need These Tools

Before we get our hands dirty, let’s make sure you have the right tools to fix the problem. You’ll need a few basics like a couple of clean rags, WD 40 spray for the terminals a wrench, a spark plug socket remover, a multimeter, and a screw driver.

Checking the Basics

The Battery

Checking the Battery on an Electric Start 50cc Scooter:

Turn off the scooter and remove the seat to access the battery compartment.
Visually inspect the battery for any signs of damage, leakage, or corrosion. Make sure there are no cracks or leaks in the battery casing, and there should be no white or greenish buildup around the terminals.
Check the battery fluid levels. Look for two red lines inside each battery cell; the fluid should be between these lines. If it’s low, you can add distilled water, but only if necessary.
Locate the positive (+) and negative (-) terminals on the battery. They are usually marked by red and black wires or caps. Ensure they are clean and tightly connected. If they are loose or dirty, use a wrench to tighten them or a wire brush to clean them.
Use a multimeter to measure the battery voltage. Set the multimeter to DC volts and connect the red probe to the positive terminal and the black probe to the negative terminal. The voltage should be around 12 volts when the scooter is off and around 14 volts when the scooter is running. If the voltage is too low, the battery might be discharged or faulty.
To check if the battery can hold a charge, you can use a load tester. This device applies a load to the battery and measures its performance. Alternatively, you can use a simple method with a headlight. Connect a headlight bulb to the battery terminals, and if it lights up brightly, the battery is likely in good shape.

Pull Start 50cc Scooter Doesn’t Have a Battery:

Unlike electric start scooters, pull start 50cc scooters don’t have a battery. Instead of relying on a battery to ignite the engine, they use a simple mechanism. When you give the pull cord a quick and firm tug, it spins the engine’s flywheel, creating the spark needed to start the scooter. This design makes pull start scooters more straightforward in terms of maintenance, as you won’t need to worry about battery-related issues. However, it also means you need to use a bit of muscle to get them going, which can be a good workout!

Spark Plug

Next up, is the spark plug. It’s the spark that ignites the fuel in your engine, and if it’s not working correctly, you’re going nowhere. We’ll guide you through inspecting and cleaning it.

The spark plug can be found on top of the engine, it is thick black wire and it is clipped onto the spark plug. So don’t worry if it’s a bit hard to get off at first. Spark plugs are important so you need to keep them clean and in good condition. Here are some steps you can follow to inspect and clean your spark plugs:

First, you need to remove the spark plugs from your engine. To do this, you have to disconnect the negative terminal on the battery, locate the spark plug wires (thick black cables running from the ignition coils to the top of the engine), clean any debris around the spark plugs with your rags or use WD 40 to help remove any dirt or grime. Then, you have to disconnect the spark plug wire to do this use a spark plug socket to unscrew the plug from the cylinder head. You can refer to this video for more details on how to remove spark plugs.
Next, you need to inspect the spark plugs for any signs of damage or wear. You should look at the electrode, which is the small metal tip that sticks out of the end of the plug, and the insulator, which is the white ceramic part that surrounds the electrode. You should also check the gap, which is the distance between the electrode and the metal arm that bends over it. Some common problems you may find are:
Carbon deposits: These are black or gray sooty deposits on the electrode and insulator, caused by rich fuel mixture or poor ignition. They can reduce the spark energy and cause misfires.
Oil deposits: These are oily or wet deposits on the electrode and insulator, caused by worn piston rings or valve seals that allow oil to leak into the combustion chamber. They can foul the spark plug and prevent it from sparking.
Ash deposits: These are light brown or white deposits on the electrode and insulator, caused by additives in low-quality fuel or oil. They can clog the gap and reduce the spark voltage.
Erosion: This is when the electrode or metal arm is worn away by high temperatures or voltage, causing them to become thinner or shorter. This can increase the gap and reduce the spark intensity.
Corrosion: This is when the electrode or metal arm is rusted or oxidized by moisture or chemicals, causing them to become rough or pitted. This can decrease the conductivity and increase the resistance of the spark plug.
Cracks: These are when the insulator or metal shell is cracked or broken by thermal shock or mechanical stress, causing them to lose their insulation or seal. This can allow leakage of current or compression, resulting in poor performance or engine damage.

You can refer to this article for more information on how to inspect spark plugs and what they tell you about your engine condition.

Cleaning and Inspecting the Spark Plug

Finally, you need to clean the spark plugs if they are dirty but not damaged. There are different methods you can use to clean spark plugs, depending on what kind of deposits they have and what tools you have available. Some common methods are:

1. Cleaning with abrasives: This is when you use sandpaper, a file, or a wire brush to scrape off any carbon, oil, or ash deposits from the electrode and insulator. You should use a fine-grit sandpaper (220-grit or higher) and be careful not to damage or widen the gap. You should also blow away any loose debris with compressed air after cleaning. You can refer to this article for more details on how to clean spark plugs with abrasives.
2. Cleaning with a blow torch: This is when you use a blow torch or a gas stove to burn off any carbon, oil, or ash deposits from the electrode and insulator. You should hold the spark plug with pliers and heat it until it glows red, then let it cool down naturally. You should avoid overheating or quenching the spark plug, as this can cause cracks or warping. You can refer to this video for more details on how to clean spark plugs with a blow torch.
3. Cleaning with a carburetor cleaner: This is when you use a spray can of carburetor cleaner to dissolve any carbon, oil, or ash deposits from the electrode and insulator. You should place the spark plug on a clean surface and spray it generously with the cleaner, then wipe it with a clean cloth. You should also use a wire brush if needed to remove any stubborn deposits. You can refer to this article for more details on how to clean spark plugs with a carburetor cleaner.

After cleaning your spark plugs, you should check their gap again and adjust it if needed according to your vehicle’s specifications. You can use a feeler gauge or a spark plug gapping tool to measure and adjust the gap. You can refer to this video for more details on how to check and change spark plugs. Then, you can reinstall your spark plugs in the reverse order of removal, making sure to tighten them properly and reconnect the wires correctly.

Fuel System

Now, let’s make sure your scooter is getting the right fuel flow. Sometimes, it’s as simple as a clogged fuel line or a dirty fuel filter. How to clean a fuel line on a 50cc scooter and how to clean the fuel filter

Fuel filter

DIY Fuel Line and Fuel Filter Cleaning:

Tools and Materials You’ll Need:

A pair of pliers
A screwdriver
A small container
A clean cloth or paper towels
A can of carburetor cleaner (available at auto parts stores)

Steps:

Safety First: Turn off the scooter’s engine and let it cool down if it’s been running recently. Ensure you’re in a well-ventilated area.
Locate the Fuel Filter: On most 50cc scooters, the fuel filter is a small, cylindrical device connected to the fuel line near the carburetor. You don’t need to disconnect the battery for this DIY cleaning.
Remove the Fuel Filter: Use pliers to gently squeeze the hose clamps on both sides of the fuel filter. Slide the clamps away from the filter. Carefully pull the fuel lines off both ends of the filter. Have a small container ready to catch any fuel that might spill.
Inspect the Fuel Filter: Examine the filter for any visible debris or clogs. If it looks dirty or clogged, it needs cleaning.
Clean the Fuel Filter: Spray carburetor cleaner into both ends of the fuel filter to flush out any dirt or blockages. Allow it to sit for a few minutes.
Rinse and Dry: Rinse the filter with clean water to remove the cleaner and debris. Shake off excess water and use a clean cloth or paper towels to pat it dry.
Check the Fuel Lines: While you have the fuel lines disconnected, inspect them for any visible clogs or damage. If you see debris, blow air through the lines or use a small pipe cleaner to clear them.
Reassemble: Reconnect the fuel lines to both ends of the fuel filter, ensuring they are secure. Slide the hose clamps back into place and tighten them with pliers.
Test Run: Start your scooter and let it run for a few minutes to ensure proper fuel flow and performance.

This DIY approach is more straightforward and doesn’t require as many specialized tools. It’s a good way to address common fuel line and filter issues on your 50cc scooter.

Common Issues and Solutions

Clogged Carburetor

One common culprit for a scooter that won’t start is a clogged carburetor. We’ll show you how to diagnose and clean it out.

DIY Cleaning for a Clogged Carburetor:

Tools and Materials You’ll Need:

A screwdriver or wrench (to remove the carburetor)
A can of carburetor cleaner (available at auto parts stores)
A small container for soaking parts
A clean cloth or paper towels
Safety goggles and gloves

Steps:

Safety First: Ensure the scooter is turned off, and let it cool down if it has been running recently. Work in a well-ventilated area, and wear safety goggles and gloves to protect your eyes and hands.
Locate the Carburetor: The carburetor is usually situated near the engine and connected to the air filter. It’s a boxy or cylindrical component with various hoses and bolts.
Remove the Carburetor: Use a screwdriver or wrench to carefully disconnect the hoses and bolts securing the carburetor to the engine. Keep track of the hoses and their positions for reassembly.
Disassemble the Carburetor: Take the carburetor apart by removing the top cover. Inside, you’ll find the float and needle valve, which are often the culprits of clogs.
Soak the Parts: Place the disassembled parts (except for rubber components) in a small container filled with carburetor cleaner. Let them soak for about 30 minutes or as recommended on the cleaner’s label.
Clean the Jets and Passages: Use the carburetor cleaner and a can of compressed air to clean the tiny jets and passages within the carburetor. Be thorough but gentle to avoid damaging delicate parts.
Inspect and Reassemble: After cleaning, inspect the parts for any remaining debris. Reassemble the carburetor, making sure to secure all hoses and bolts as they were before.
Reattach the Carburetor: Carefully reconnect the carburetor to the engine, ensuring all hoses are correctly attached and bolts are tightened snugly.
Test Start: Start your scooter and let it run for a few minutes to ensure it’s running smoothly without any issues.

Poorly Mixed Oil and Gas

If the fuel mix is not properly mixed, it can cause damage to the engine.

To tell if a 2-stroke fuel mix is bad, you can check for a spoiled varnish-like odor, a murky darker appearance not indicative of oil mix color, or if it has been in storage for more than a month . If any of these conditions are present with your two-stroke mixed fuel, do not use it in your engine.

Did you know that gasoline can go bad? Stale fuel can gum up your engine and make it impossible to start. Learn how to avoid this issue.

Changing the fuel can be a good troubleshooting step if you suspect that the current fuel in your scooter might be causing starting problems. Here’s what you can do:

Drain the Old Fuel: If you think the fuel in your scooter is old or stale, consider draining it from the tank. Stale fuel can lead to starting issues.
Refill with Fresh Fuel: After draining the old fuel, refill the tank with fresh, high-quality gasoline. Make sure the gasoline is suitable for your scooter’s engine.
Check the Oil-Fuel Mix: If your scooter requires a specific oil-fuel mixture, ensure that you’ve mixed it correctly. Using the right oil and the correct ratio is crucial.
Prime the Fuel System: After refilling with fresh fuel, you may need to prime the fuel system to ensure that the new fuel reaches the carburetor properly. Consult your scooter’s manual for instructions on how to prime it.
Attempt to Start: Try starting your scooter with fresh fuel. If the previous fuel was the issue, this step should resolve the starting problem.

Changing the fuel is a practical step if you suspect that the fuel quality or age is causing the problem. However, if your scooter still doesn’t start after these steps, there might be other issues like a clogged carburetor, ignition problems, or spark plug issues that should be investigated further.

Some 50cc scooters need oil mixed with their fuel to run correctly. This oil-fuel mixture helps lubricate the engine parts and keeps them running smoothly. If your scooter doesn’t start, it might be because the oil-to-fuel ratio isn’t right.

Imagine making a cake: if you don’t have the right amount of ingredients, like too little sugar or too much flour, the cake won’t turn out right. Similarly, if your scooter doesn’t have the correct mix of oil and fuel, the engine won’t work correctly, and it won’t start.

So, if your scooter isn’t starting, it’s a good idea to check the oil-fuel mixture. Make sure you’re using the right type of oil and that the ratio is correct. Adjusting this mix can often solve starting problems and keep your scooter running smoothly.

Stale Fuel

When gasoline gets old, it can turn into a problem called “stale fuel.” Stale fuel isn’t good for your scooter because it can become thick and sticky, almost like gum. When you try to start your scooter with stale fuel, it can clog up your engine, making it really tough or even impossible to start.

To avoid this issue, it’s essential to use fresh gasoline. Don’t leave the same gas sitting in your scooter for too long, especially if you’re not riding it regularly. If you’re storing your scooter for an extended period, consider using a fuel stabilizer. This special liquid helps keep your gasoline fresh and prevents it from turning into sticky goo. By using fresh gas and a fuel stabilizer when needed, you can keep your scooter’s engine running smoothly and avoid starting problems caused by stale fuel.

Faulty Ignition System

Electrical Problems

Sometimes, it’s the wiring and electrical connections that cause trouble. We’ll help you troubleshoot these issues step by step.

Troubleshooting Electrical Issues on Your Scooter:

Check the Battery: First, make sure your scooter’s battery is charged. If it’s dead or weak, your scooter won’t start. Connect it to a charger or replace it if needed.
Inspect the Wiring: Look for any visibly damaged or frayed wires. If you see exposed wires or wires that look worn out, they may need to be repaired or replaced.
Test the Spark Plug: Ensure that the spark plug is in good condition. If it’s dirty or worn, clean it or replace it. A faulty spark plug can prevent your scooter from starting.
Examine Fuses: Locate the fuse box on your scooter and check for blown fuses. If you find any, replace them with fuses of the same rating.
Ignition Switch: Test the ignition switch by turning it on and off several times. If it feels loose or doesn’t function correctly, it may need to be repaired or replaced.
Kill Switch: Check if the kill switch is in the “off” position. Sometimes, it can accidentally get switched off, preventing your scooter from starting.
Starter Solenoid: Test the starter solenoid by listening for a click when you try to start the scooter. If you don’t hear a click, the solenoid may be faulty.
Ground Connections: Ensure that all ground connections are secure and free from corrosion. Clean and tighten them if necessary.
Inspect the Wiring Harness: Examine the wiring harness for any loose or disconnected connections. Reconnect any wires that may have come loose.
Test the Voltage: Use a multimeter to measure the voltage at various points in the electrical system, including the battery terminals, ignition switch, and spark plug. Ensure that you have the correct voltage at each point.
Replace Faulty Components: If you identify any faulty components during your checks, such as a damaged wire or a malfunctioning switch, replace or repair them as needed.
Consult a Professional: If you’ve gone through these steps and still can’t identify or fix the electrical issue, it may be time to consult a professional scooter mechanic or electrician for a more in-depth diagnosis and repair.

By following these simple steps, you can troubleshoot and address common electrical issues that may be preventing your scooter from starting.

Regular Maintenance Tips

Regular Maintenance: Preventing Scooter Problems

Saves Money: Regular maintenance can cost less than major repairs. Spending a little on maintenance now can save you from spending a lot on repairs later.
Extends Lifespan: Proper maintenance can extend your scooter’s life. It’s like giving it extra years to ride: 2 years of maintenance can equal 5 more years of use!
Keeps It Safe: Well-maintained scooters are safer. 3 out of 5 accidents happen due to mechanical issues. Maintenance reduces the risk by 70%.
Boosts Fuel Efficiency: Good maintenance can save you money at the gas pump. It can improve mileage by up to 10%, meaning more rides for your money.
Avoids Breakdowns: Regular checks reduce breakdowns by 80%. Imagine avoiding 4 out of 5 times you could get stuck!

So, remember, taking care of your scooter regularly is like a magic formula: it saves money, makes it last longer, keeps you safe, saves on gas, and avoids frustrating breakdowns.

Winter Storage

If you’re not riding your scooter during the winter months, there are some essential steps to take to ensure it starts up when spring comes around again.

For 2-Stroke 50cc Scooters:

Fuel Stabilization:
- Before storing your 2-stroke scooter for the winter, add a fuel stabilizer to the gas tank and run the engine for a few minutes. This helps prevent the fuel from going bad and gumming up the carburetor.
- After running the engine with the stabilizer, turn off the fuel supply and let the engine run until it stalls. This ensures that the stabilized fuel is in the carburetor, protecting it from varnish and clogs during storage.
Remove the Battery:
- If your 2-stroke scooter has a battery (for electric start or lights), remove it from the scooter during storage.
- Store the battery in a cool, dry place and keep it charged to prevent it from losing power or freezing during the winter.

For Electric Start Scooters:

Battery Maintenance:
- Ensure your scooter’s battery is fully charged before storing it. A well-charged battery is crucial for electric start scooters.
- Consider using a battery maintainer or tender during storage to keep the battery in good condition. These devices automatically charge and maintain the battery at the right voltage.
Cover and Shelter:
- Keep your electric start scooter in a sheltered area, like a garage or shed, to protect it from the harsh winter elements.
- Use a scooter cover to shield it from dust and moisture, even if it’s stored indoors.

By following these steps, you’ll help ensure that both your 2-stroke and electric start scooters start up smoothly and reliably when spring arrives, making your riding experience hassle-free.

Get Back on the Road

There you have it, your comprehensive guide to troubleshooting a 50cc scooter that won’t start. We’ve covered everything from the basics of spark and fuel to common issues and regular maintenance tips. Now it’s time to put your newfound knowledge to use and get back on the road. Happy scooting!

49cc Scooter Buyers Guide

FAQs

Q1: Why won’t my scooter start even though it has spark and fuel? A1: Having spark and fuel is necessary but not sufficient for starting your scooter. There could be other issues like a clogged carburetor, a faulty ignition system, or electrical problems that need attention.

Q2: Can I clean the spark plug myself? A2: Absolutely! Cleaning the spark plug is a simple task. Just follow our guide in the article to do it safely.

Q3: How often should I perform regular maintenance on my scooter? A3: Regular maintenance should be done according to your scooter’s owner’s manual. Typically, it’s recommended every 1,000 miles or at least once a year.

Q4: What’s the best way to store my scooter during the winter months? A4: Proper winter storage involves steps like stabilizing the fuel, protecting the battery, and covering the scooter. Check our article’s section on Winter Storage for detailed instructions.

Q5: Can a grade eight student really follow these instructions? A5: Absolutely! We’ve written this guide in a way that’s easy to understand, even for someone as young as a grade eight student. Just follow the steps, and you’ll be on your way to fixing your scooter!

49cc Scooter Buyers Guide