Motorcycle Won't Start? Check These 8 Things First
Before you call a tow truck or panic, run through this checklist. Most no-start situations have simple fixes you can handle yourself.
MMNM
Your motorcycle won't start. You're standing in the garage, helmet in hand, increasingly frustrated.
Before you assume the worst, work through this checklist. Most no-start situations come down to something simple.
Before You Start
Listen to what happens when you hit the starter:
Nothing at all? Likely electrical. Battery, connections, or safety switches.
Clicking but no crank? Battery is weak or starter motor issues.
Cranks but won't fire? Fuel or ignition problem.
Cranks, fires briefly, dies? Fuel delivery or air issue.
Knowing which category you're in helps narrow down the problem.
The Checklist
1. Kill Switch
Laugh if you want, but check it anyway.
The kill switch is there because it's meant to be used in emergencies. It's also there to embarrass you when you forget you flipped it.
Slide it to the "run" position. Try again.
2. Kickstand Safety Switch
Most modern bikes won't start in gear with the kickstand down. Some won't start at all with the kickstand down.
Put the kickstand up. Put the bike in neutral. Try again.
If it starts in neutral but not in gear with the clutch pulled, your clutch safety switch might be failing.
3. Battery Condition
A weak battery is the most common cause of no-starts.
Signs of a weak battery:
- Dash lights dim when you hit the starter
- Starter sounds slow or labored
- Clicking noise instead of cranking
- Nothing happens at all
Check the terminals first. Corrosion (white or green buildup) can prevent good contact. Clean with a wire brush and reconnect.
If the battery is more than 3-4 years old and you've been having starting issues, it's probably time for a new one. Don't wait for it to strand you.
4. Fuel
If the bike sat for more than a few weeks, fuel could be the issue.
Check the petcock (if equipped) is in the "on" or "reserve" position. Vacuum-operated petcocks can fail, preventing fuel flow.
If the bike sat for months with fuel in the tank, that fuel is probably varnished. The carburetors or injectors may be gummed up. This requires more involved work.
Fuel-injected bikes: listen for the fuel pump priming when you turn the key. You should hear a brief whine. No sound means the pump isn't running.
5. Fuel Tank Vent
The fuel tank needs to breathe. If the vent is clogged, vacuum builds up and fuel can't flow properly.
Symptom: bike starts and runs for a minute or two, then dies. Loosening the gas cap temporarily fixes it.
Check the vent line for obstructions. Replace the gas cap if the internal vent is damaged.
6. Spark Plugs
Pull a spark plug and inspect it.
Wet with fuel? The engine is getting gas but not spark. Could be ignition coil, plug wires, or the plug itself.
Dry? Fuel isn't reaching the cylinder. Check fuel delivery.
Black and fouled? Engine is running rich or oil is getting past the rings.
White and clean? Engine is running lean. Air leak or fuel delivery problem.
If the plug looks questionable, swap in a fresh one. They're cheap insurance.
7. Air Filter
A severely clogged air filter can prevent starting or cause immediate stalling.
Pull the filter and inspect it. If it's black with dirt, replace it. If it's oiled foam, clean and re-oil it.
Don't run the bike without a filter, even briefly. One piece of debris in the cylinder causes expensive damage.
8. Fuses
Modern bikes have multiple fuses protecting different systems. A blown fuse can prevent starting.
Check the main fuse first, usually near the battery. Then check the ignition and fuel pump fuses.
Carry spare fuses in your toolkit. The one time you need them, you'll be glad you did.
When to Call a Pro
Work through the checklist twice. If the bike still won't start, you're into territory that requires diagnosis:
Compression issues. Valves out of adjustment, worn rings, or head gasket problems prevent the engine from building pressure.
Ignition timing. If the spark is happening at the wrong time, the engine won't run properly.
ECU problems. On modern bikes, the computer controls everything. When it fails, diagnosis requires specialized equipment.
Internal engine damage. Catastrophic failures obviously require professional help.
Don't throw parts at the problem hoping something works. That gets expensive quickly. If the basic checklist doesn't solve it, a mechanic with proper diagnostic equipment will save you time and money.
Prevention
Most no-start situations are preventable:
- Start the bike at least every two weeks if it's sitting
- Use fuel stabilizer if storing for more than a month
- Keep the battery on a tender when not riding
- Follow the maintenance schedule for spark plugs and filters
- Address small issues before they become big ones
A well-maintained bike starts reliably. When it doesn't, work the checklist before assuming the worst.
