10 Reasons A Motorcycle Won’t Start-After Sitting For Months

We all know the frustration of trying to get a dead bike to start, especially on the first few beautiful riding days after the cold, unrideable winter.

The motorcycle might have been garaged for the bad weather season, or you simply want to take it out of storage and dust off your riding skills, but it just won’t start!

We’ll run you through a checklist of 10 reasons why a motorcycle won’t start after sitting for months. Take a look at our tips on what to look out for (it could be simpler than you think)!

1. Your Battery Might Be Dead

During long storage periods, motorcycle batteries with low charge can drain away their life. This is especially problematic in extreme temperatures, both hot and cold.

Freezing temperatures are a common culprit to absolute battery drain because the extreme cold can freeze the battery and destroy it.  

Chances are, your bike has an electric starter in place of the outdated kick-starters that once graced the side of every steel pony. The only downside to an electric-started motorcycle is when there’s no juice from the battery, there’s nothing to power the starter! 

One way to test your battery for power is a simple voltmeter. If you don’t have one in your motorcycle tool kit, don’t worry-basic voltmeters are available at practically any auto parts store for just a few bucks. Put the probes on both battery terminals to check and see if you have voltage. 

If your battery is fully charged, it should read between 12.6 and 12.8 volts and you can move on to another section to find out why your motorcycle won’t start after sitting for months. But if your voltage is significantly lower than this range, it means that the battery should be replaced. 

One excellent device that’s saved our butts over the years is a battery tender, also known as a trickle charger. For any long periods of storage, you can plug your battery into the charger and keep it at tip-top voltage. That way, anytime you want to get up and go, your bike will start right up with no problems from the battery!

2. Choke Your Bike!

A motorcycle choke literally chokes the air out of the air/fuel mix to enrich the amount of fuel that’s available for combustion.

When your bike wants to start and you hear the puttering from the engine, but it just won’t fire up properly, go ahead and use your choke lever or plunger to give the engine the right conditions to combust properly.

The choke function for motorcycles is especially key on cold mornings when starting up a bike that’s been sitting for a few months proves to be a hassle!

If your choke function works out to get the bike started, let it idle for a couple of minutes before de-choking the bike and letting the correct amount of air into the mixture.

Make sure to let off the choke before you ride, as using an improper air/fuel mixture can foul your spark plugs or even damage your motorcycle’s engine.

3. Check for Loose Or Corroded Wiring

Let’s face it-long-term storage, even for a couple of months, can wreak havoc on your wiring harness.

Moisture can take over the oxidization process on wires that weren’t corroded enough to cause problems when you were using your daily rider and if your steed sat in a humid environment that corrosion is now a bigger problem.

When it comes to loose or corroded wiring, another dastardly set of reprobates are rodents. Unfortunately, mice, rats, and squirrels can chew through wiring that was perfectly good when it last ran. 

You might need to remove your seat for this one, but take a good look at your wiring harness. Are there areas where wiring that should be encased in thermoplastic is bare for any reason? It is possible that you might need to take your motorcycle to a trusted repair shop and have them go through your wiring.

When wiring has become damaged or corroded, it can lead to bigger problems such as long-term voltage drain.  

Related: Motorcycle Won’t Start But Battery Is Good? (Solved)

4. Was the Fuel Tank Drained When the Motorcycle Was Garaged?

It is common practice to drain the fuel out of your fuel system when storing a motorcycle. This is because gasoline simply goes bad over time.

When fuel sits in the tank and fuel system over time, the chemical bonds in the gasoline break down. On top of that, moisture can collect in the fuel and cause all sorts of problems. 

Open up that tank and check to make sure you have any fuel in the first place! If you’re not sure how long the bike has been sitting, it’s a good idea to drain out the fuel and replace it with good fuel to make sure you won’t be gumming up the works or damaging your engine.

5. Are Your Fuel Lines Clogged?

Over time, fuel lines can become clogged with ethanol-based fuels, sediment, and corrosion that forms inside an old fuel system. When this happens, the fuel can’t leave the tank and enter your carburetor or fuel injectors to deliver it properly to the engine. 

If you suspect that your fuel lines are clogged, close your fuel valve or petcock and remove the fuel lines leading to the carburetor or fuel injectors.

Even though we definitely recommend replacing any fuel lines that have been clogged with bad gas, sediment, corrosion, or debris, it might be a good idea to use some compressed air to blow them out and see what the root of the problem is.

6. Bad Fuses Can Keep Your Bike From Starting

Motorcycles with electrical systems have fuses, just like any other vehicle. The fuses work as fail-safe devices to prevent electrical overload from one part of the system from affecting any other part of the system.

Locate the fuse box on your motorcycle. Take out each fuse and make sure that it is intact. It’s always a good idea to keep some spare fuses on hand for this purpose. If any of your fuses have been blown, replace them with the appropriately sized fuse and try to start the bike.

When a fuse has blown, it is important to note which electrical system or component on the motorcycle it functions for.

A blown fuse is an indicator of a bigger electrical problem and, chances are that the system might need a once over to check for what might have caused the voltage surge that blew that fuse. 

Related: How To Tell If A Motorcycle Fuse Is Blown (Explained)

7. Check The Exhaust Pipes For Debris

As obvious as it may seem, check your exhaust pipes for anything that might have obstructed their ability to let the exhaust out of the motorcycle.

Bikes that have sat in storage for months or longer may have had something stuffed in the exhaust to keep debris from entering the engine from the exhaust side. 

8. Electric Starters Can Go Bad

Much like death and taxes, it is inevitable that an electric starter will one day go bad. If your battery is reading 12.6 to 12.8 volts and you still can’t even get a peep out of the bike when you go to start it, this might be the case.

You can use your handy voltmeter to Ohm out the starter (check to see if the electrical current is running through it properly).

If your starter has gone bad after sitting for months, it’s time to replace it. 

9. Fouled Spark Plugs Stop You Dead in Your Tracks

Even if your bike would begrudgingly fire up when it was running several months ago, fouled spark plugs can keep you from starting a motorcycle. Fortunately, it is a pretty easy test to check and see if your spark plugs have corroded or fouled.

Loosen the spark plugs with the appropriately sized socket and remove them. If they are very tarnished with black soot from running fuel-rich, or with a white, powdery detritus from running lean, it’s time to replace those suckers!

Spark plugs sit in the engine head where they produce the cycling electrical component to combustion. If they are corroded or fouled, the engine simply cannot explode the fuel/air mist that is sucked into the combustion chamber and your bike won’t start!

These simple little devices are cheap and easy to replace. We recommend having some extras on hand to start up a motorcycle that’s been sitting for months, or longer.

Related: Motorcycle Won’t Kickstart | Here’s Why (Solved)

10. Motorcycle Won’t Start With Old Gas

It was once commonly understood that fuel could sit for 6 months to a year without having much of a problem. Nowadays, fuel contains a reprehensible amount of ethanol.

The chemical bonds in ethanol break down much more quickly than the cleaner gas of yesteryear, so even after a couple of months, it can go bad. 

If bad gas gets cycled through your combustion system, it can cause a wide range of problems. Sometimes, simply adding a good amount of good gas to the tank can make a mixture that is acceptable for the engine to burn through the bad particles. 

It’s always a good idea to drain your entire fuel system before storing a motorcycle, but we say better late than never! Draining your tank is a good idea after a motorcycle has sat for months, even if you think the fuel is still good.

How to Start a Bike After 2 Years

If a motorcycle has sat in storage for 2 years, it’s a good idea to start from the ground up. Here’s a simple checklist for things you’ll want to do so you can get that hog on the road!

  • Drain the fuel from the tank, fuel lines, and carburetor. Refill with high-quality fuel and consider adding in a non-detergent fuel cleaner.
  • Check the spark plugs for any fouling and corrosion. Replace as the need may be.
  • Chances are, a 2-year-old battery isn’t going to be good anymore. Grab a new battery and throw it in the harness!
  • Do a visual inspection of the fuel lines, brake lines, wiring harness/electrical system, exhaust pipes, and engine block. 
  • Choke the bike. With any luck, this will give a rich enough mixture for proper combustion after sitting for so long.
  • Start it up! Make sure to take it slow and easy with any motorcycle that has sat for 2 or more years. Chances are you’ll need to tune the carburetor.

Sources

How a Choke Works in Motorcycles | Venhill UK

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