Winter can be hard on your motorcycle. Months of sitting idle in a cold garage or storage unit can cause problems that show up the moment you try to fire it up. If your motorcycle won’t start after winter, you’re not alone—and it’s not always about the battery. At Tow Mates, we get this question a lot: Can you jump start a motorcycle with a portable jump starter? The short answer is yes, but there’s more to it than just connecting cables and pushing a button.
Let’s break it down step by step so you understand what causes these starting issues, what you can do to prevent them, and how to get your bike back on the road safely.
Why Your Motorcycle Won’t Start After Winter
There’s nothing worse than planning your first ride of the season, only to find that your motorcycle won’t start after winter. Several key systems can suffer during months of cold and inactivity.
The Battery Is Usually the First Suspect
Cold weather drains battery voltage. If your bike’s been sitting for months, the battery may have lost charge or even developed internal corrosion. Low voltage is one of the most common reasons a motorcycle won’t start after winter, especially if you didn’t keep it on a trickle charger.
Fuel Problems in the Tank and System
Old fuel can break down over time, especially when left sitting for months in a cold tank. That stale gas can clog the carburetor or fuel injectors, causing start-up issues. Moisture in the fuel system can also lead to corrosion, which affects performance and causes further problems.
Oil Thickens in Cold Conditions
Oil can thicken in lower temperatures, making it harder for the engine to turn over. If your oil hasn’t been changed in a while, the build-up of particles may also reduce performance and increase wear during start-up.
How to Safely Jump Start Your Motorcycle
Before doing anything, confirm that a dead battery is really the issue. If your lights are dim or there’s no click when you hit the ignition switch, it’s likely the battery. Here’s how to jump start it safely:
What You’ll Need
- A portable jump starter rated for motorcycles (check the voltage)
- Safety gloves
- A clear, dry location
- Eye protection (just in case of sparks)
Step-by-Step Instructions
- Switch off everything on the motorcycle before attaching anything
- Connect the positive (red) clamp to the positive terminal of the motorcycle battery
- Connect the negative (black) clamp to a grounded metal part of the frame—not directly to the negative terminal
- Power on the jump starter
- Try starting the motorcycle
- Once started, disconnect the clamps in reverse order and let the engine run for 10–15 minutes to recharge the battery
Never keep the jump starter connected for too long, and always read your jump starter’s manual. Over-voltage can damage the bike’s wiring or starter.
Other Reasons a Motorcycle Won’t Start After Winter
If jumping doesn’t work, the battery might not be the only problem.
Corroded Wires and Terminals
Battery terminals, starter wires, or grounding points may develop corrosion in damp winter air. Clean contacts ensure better electrical flow, so inspect them closely.
Blown Fuse or Faulty Starter
If your lights turn on but the bike won’t crank, a fuse or the starter motor itself might be faulty. Check your fuse box and look for any blown fuses before moving forward.
Bad Spark Plug or Plug Wires
No spark, no start. If your plug is dirty or your plug wires are cracked or brittle, it can prevent ignition. This is especially true after months of cold air and moisture.
Keeping Your Motorcycle Safe During Winter Storage
To avoid the “motorcycle won’t start after winter” scenario next season, here’s what we at Tow Mates suggest:
Fuel Stabiliser in the Tank
Adding a stabiliser to your gas tank prevents the fuel from breaking down over time and keeps your carburetor or injectors clean.
Keep the Battery Charged
Use a trickle charger or battery tender to keep the voltage steady. This helps preserve battery health over several months of non-use.
Change the Oil Before Storage
Fresh oil helps prevent internal engine damage during cold starts and reduces buildup while the bike is not in use.
Cover and Ventilate
Use a breathable motorcycle cover and store your bike in a dry, sheltered area. Keep airflow going to prevent moisture buildup, which can lead to corrosion.
Signs That It’s Time for Professional Help
If you’ve tried jump starting and checked the basics but the motorcycle still won’t start after winter, it might be time to bring in a pro. Look out for:
- Flickering dashboard lights
- Unusual clicking or buzzing sounds from the engine
- Burning smell or visible smoke
- Battery won’t hold charge even after a jump
- Starter spins but engine doesn’t catch
At Tow Mates, we assist riders who find themselves stuck on the side of the road or dealing with repeated starting issues after long storage periods. Getting your motorcycle serviced early in the season can help prevent more serious repairs later.
Conclusion:
If your motorcycle won’t start after winter, a portable jump starter can get you rolling again, but it’s not a one-size-fits-all solution. You’ll need to inspect the battery, fuel, spark, and oil system to ensure your ride is road-ready.
When in doubt, always prioritise safety. A rushed fix can cause more harm than good. With some basic checks, quality tools, and good maintenance habits, your motorcycle can perform just as well after a long winter as it did before.
And if all else fails, Tow Mates is always here to help get your bike back on the road.