Motorcycle Won’t Start When Hot? Here’s How to Fix It!


If your motorcycle won’t start when it’s warm or hot, it’s not of very much use, now is it? Unfortunately it can happen even to the finest bikes and even if you maintain yours regularly. It’s because about 50 things could go wrong and cause this issue.

In this article at the beginning you’ll find 9 useful ways to resolve this issue that work in most cases. I’ve also made a comprehensive list of 50 potential causes that you can troubleshoot further if those 9 tips don’t work for you. So the following text will definitely help you pinpoint the cause and fix it as soon as possible.

Helpful Tips & Tricks to Solve The Problem

Let’s get to the basics.

To start a motorcycle, you need three things. They are:

  • Gas
  • Spark
  • Cylinder compression

If your motorcycle has an electrical starter, then you need these four steps to start the motorcycle:

  • Turn on the ignition.
  • The “kill switch” on the right handle should be in the “on” position.
  • Squeeze the rear left brake.
  • Press on the starter button.

Quick takeaways:

  • Use choke
  • If you didn’t use your motorcycle for a long time, then you need to put new gas in it.
  • Clean the air filter
  • Clean the carburetor

Easy ways to get your motorcycle started when it’s hot:

  • Change your spark plug
  • Clean out the fuel tank
  • Replace fuel in the fuel tank with fresh fuel
  • Put in some form of fuel system cleaner

1. Check if it’s the spark plug

Safety tip: AVOID holding anything metal.

This method is for experts only: Take out the spark plug from the head but not out of the boot. Place it against a metal piece of your motorcycle. Turn it over while kicking the kickstart. If you have an electric start, then use that. You should be able to see a spark now.

  • If yes, then well and good.
  • If not, then you need to put a new spark plug.

You need to ensure you put the right sparkplug in, and you should not overtighten it.

2. Check the ignition system

Mostly the problem lies in the engine, that won’t receive the right spark, and so your motorcycle won’t start. If you are an experienced motorcycle rider, then you would know where to do what, especially when it comes to the electrical components. But if you don’t know, then you should go to a certified mechanic to help you solve the problem and get a complete diagnostic check-up done on your motorcycle.

3. Engage the clutch of your motorcycle

A walk in the park for experienced riders, but newcomers, it is important to engage the clutch to avoid having a frustrating trip. Even when you are in neutral, you must have the clutch in.

Make sure your motorcycle’s clutch switch has no damage. You can try pumping the clutch a few times to check if it resets. This solution is not for a long-term, you may need a clutch replacement in the future.

4. Put up the side stand

Some motorcycles may not start if they are on the side stand. New technology in the form of high-tech sensors could also be the reason behind it. That is, you need to avoid starting the ignition if the kickstand is down.

5. Avoid jumping the battery

This does not work always. You might have considered this possibility a thousand times. But you are only risking your motorcycle’s life by doing that. There is a microprocessor in your motorcycle, if you jumpstart it, you might fry it by spiking the voltage.

It is not suited even for a three-wheel motorcycle. You cannot apply the rules you apply to your sedan or a pickup truck. All of them have different guidelines for voltage and jumpstarting process.

6. Clean the air filter

Your motorcycle won’t start because you are not taking good care of the air filter. How dirty is the air filter? If there is mud, sand, or dirt in any form, your motorcycle won’t be starting anytime soon unless you clean it or replace it. For any filter to work, it needs to be free of particulates that can hinder it.

7. Check if there are any loose wires

Your motorcycle is an instrument of electrical components that needs plugging all the time. If there are any loose wires, then there can be electrical issues that often escape the rider’s eyes, as they are not always visible.

You need to manually check the connectors without touching any electrical part. If you suspect that the battery is the culprit, then you need a new battery. These loose wires can lead to your motorcycle’s non-starter problem.

8. What if it’s the compression

When you are running out of options, and don’t know where to go and what to do, then you have only one thing left to troubleshoot. That’s the compression. If the cylinders has low or no compression, then your motorcycle’s engine will not fire.

The appropriate mixture of air and fuel needs compression, and if it doesn’t get that at a certain temperature, then it won’t be combustible. Without appropriate compression, the mixture will not ignite.

9. Cover your motorcycle with an insulating material

Your motorcycle gets most of its heat from the sun when it is out in the open. To avoid that, you need to cover your motorcycle with an insulating material that ensures the engine does not lose its heat or get overheated. Also, it keeps dust, mud, and dirt at bay.

This will also prevent your motorcycle’s engine from getting cold in the winters.

50 Possible Reasons A Motorcycle Won’t Start When Hot

In case none of those 9 fixes helps you, here is a comprehensive list with 50 possible causes that you can explore further:

  • Engine problem- There is low or no engine oil.
  • Electrical problem- Some electrical component gets hot, and it quits working. When electrical components get hot, they give rise to resistance, and then your motorcycle stops working. Which are the parts? Coil, stator, CDI unit, or any other electrical component.
  • Wearing out of engine parts, not the gearbox.
  • The fuel tank is empty.
  • The fuel tank has old dead gas.
  • The fuel tank’s bottom part may have ethanol sludge, dirt particles, water, rust, or any other material.
  • Turn off of the petcock or fuel supply valve.
  • A severely discharged battery
  • A damaged battery
  • The carburetor float may be stuck.
  • Clogging of the fuel supply valve/petcock or filter
  • Pinching of the fuel line that goes to the carburetor or throttle body
  • You need to check the battery terminals for damage or corrosion due to rust.
  • Check the battery cables if they are loose, rusted, broken, or corroded.
  • Kinking, choking or blocking of the fuel line that goes to the carburetor or throttle body
  • Disconnection of the vacuum hose that goes to the fuel supply valve/ petcock
  • Faulty kickstand safety switch
  • Faulty fuel pump
  • Check for engine trouble codes.
  • Burning of the stuck bent or any of the valves.
  • The tilt sensor may be needing a reset option.
  • The faulty ignition coil leads to incorrect ignition timing.
  • The faulty ignition module or MAP, CKP, O2, TPS, ETP, IAC, or CMP sensors leading to incorrect ignition timing.
  • Corrosion or loosening of the wire connection between the ignition sensor and ECM module.
  • A security system that should give out alarms may need a resent option.
  • Faulty fuse
  • Faulty relay
  • The poor condition of the spark plug
  • Shorting of the spark plug
  • You must check for spark leakage
  • Cable connections may be loose
  • Cable connections connected to the wrong cylinders
  • If you know, then you must perform a connector wiggle test.
  • If you know, then check cables with an ohmmeter.
  • An over-usage of enricher may cause flooding of the engine.
  • Broken, cracking, or pinching of the vacuum hose that goes to the fuel supply valve/ petcock.
  • Foul spark plugs
  • Check if the fuel has a vapor lock.
  • The gap between the spark plug may be too wide.
  • HISS light may not be going off.
  • Faulty temperature sensors
  • Faulty condition of the starter motor
  • The valves adjusted too tight.
  • Faulty condition of the ignition coil
  • Faulty brakes or charger
  • Make sure the fuse has not blown.
  • Enricher not shutting off and flooding.
  • Faulty kill switch
  • Check for blown fuses.
  • Check the muffler.

Conclusion

Routine maintenance is a must. You cannot run away from it or procrastinate about it. If you are taking good care of your motorcycle before and after a long ride through visual checks, and necessary fluid changes, then you will not suffer a backlash on the track or trail.

Hope you have a fun ride on your motorcycle!

Luka Barron

Motorcycle mechanic, writer and Heineken lover. A bit like Hank Moody on a Suzuki.

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