What To Do When Your Motorcycle Won't Start

A methodical approach on how to start a motorcycle when you push the button and your motorcycle doesn't start

It's a beautiful morning, the sun is shining, the birds are singing. All's right with the world. It's a perfect day for a ride. You pull on your riding gear, hit the switch, and the motorcycle gods toss you a curveball: Nothing happens. Now what? Here's how to start a bike that doesn't want to turn on.

How A Motorcycle Engine Works

Internal combustion engines need three things. They must have good-quality fuel, compression, and spark delivered to the compressed fuel-air mix at the appropriate time, or very close to it. Given those three items, an engine will run. Since the majority of you probably own bikes that start with a button, the fourth item you'll need is enough electrical energy to spin the starter.

Before You Start

Figuring out how to start a motorcycle that doesn't want to turn on becomes a game of ruling out issues. Basic troubleshooting requires little in the way of tools and skills. However, you should at least feel comfortable removing a spark plug, draining a carburetor, and using a multimeter. The tools needed to perform these basic chores can be purchased at any hardware store. I'd also recommend that you buy a factory service manual or its equivalent if you plan on keeping your bike past the warranty expiration date.

A motorcycle petcock.
If your bike won’t start, double-check that you have fuel and the kill switch is not switched to stop the operation of the bike.Motorcycle Cruiser

Verify Correct Motorcycle Starting Procedure

D'oh. I hate it when that happens! At the risk of seeming condescending, you did follow the correct starting procedure, didn't you? Every motorcycle has its starting drill. Many require that the clutch be held in, whether the bike is in gear or not, and some want the bike to be in neutral anytime it's on the kickstand. Before you panic, verify the starting procedure, especially if it's a new bike that you're not entirely familiar with. It may sound obvious, but make certain that someone hasn't moved the kill switch to off, especially if you have little urchins running around who love to sit on motorcycles when mom and dad aren't watching.

Motorcycle clutch safety switch can stop the operation of a motorcycle if faulty.
Check your kickstand and safety switches, making sure they are not corroded or damaged.Motorcycle Cruiser

Dead Motorcycle Battery Symptoms

If everything is in order and she won't even spin, the most likely culprit is a bum battery or something that's preventing the battery from doing its job. Most of us are familiar enough with the conspicuous signs of a dead battery: dim lights, a weak horn, and slow or no starter activity. Push the horn button; if the horn sounds anemic, the battery is probably the culprit.

If that seems to be the situation, it's time to charge or possibly replace the battery. Before you do though, check the battery terminal connections. It's possible the terminals are loose or corroded, and good cleaning and tightening are all they need. Follow that up with a voltmeter reading across the battery terminals, or a hydrometer reading of the cells. If the voltmeter reads above 12.2 volts (no load), 11.5 volts with the lights on, or the hydrometer reads less than 1.265 (less than four balls floating), it's time to service and recharge the battery.

Jump Starting A Motorcycle

Charging the battery is going to take some time. You may be tempted to try and jump start your bike from your car or a buddy's bike. It can be done, and in the past, I've certainly done it. However, many newer motorcycles, particularly those that are fuel-injected, utilize some sort of microprocessor. Computers are highly sensitive to voltage spikes, and nothing causes a spike quite like a jump start. If you're unsure about the jump starting procedure for your bike, play it safe and sit this dance out.

To jump start a motorcycle with a car, ensure your car’s battery is in top condition and the car and motorcycle ignitions are both in the off position. Expose the battery terminals on both bike and car, connecting the positive (red) clamp to the positive post on the motorcycle battery first, and then the positive post on the car battery. Make sure the negative (black) clamps are not touching anything.

Next, connect the negative clamp to the negative post on the car and then connect the negative clamp to any unpainted part of your bike, away from the fuel tank and lines, preferably the footpeg. Do not turn on the car! This can damage your battery and possibly fry your electrical system. Start your bike as you normally would.

If the bike doesn’t start after 10 seconds of cranking, give it a rest, you don’t want to burn out your starter. After a minute, repeat the starting process and wait for the starter to cool. Try once more. If at this point your bike doesn’t start, then check the voltage on your battery—with the jumper cables disconnected—and determine if charging is an option.

If your bike starts, disconnect your negative cables at the motorcycle first, then the car. Now you can remove the positive cables and put them away. Do not turn your bike off. Your alternator or generator hasn’t begun to substantially charge your battery and you’ll be back at square one. Take the long way to wherever you’re going to ensure your bike’s charging system has provided enough juice to the battery for the next time you start it. Also, pack the jumper cables in a bag and take them with you.

Motorcycle Won't Start But Battery Is Good

The worst-case scenario is going to be a good battery and no action at the starter motor. If that turns out to be the case, you'll need to do some troubleshooting. Start with the simple things. Likely trouble spots include a blown fuse, or a malfunctioning kickstand safety switch or clutch/starter interlock switch.

If the culprit is a blown fuse, replace it with one that carries the same amperage rating and give her another try. If the fuse blows again, you've got a dead short somewhere, which will need to be repaired before you go much further. If one of the switches is suspect, they can be bypassed with a jumper wire to get you back on the road.

Bypass of a motorcycle safety switch using a short piece of wire.
For a quick fix, you can always bypass your safety switches with a short piece of wire.Motorcycle Cruiser

Motorcycle Starter Spins But Won't Catch?

If the bike turns over normally without laboring, chances are pretty good the problem lies in either the fuel or ignition system, particularly if the bike was running fine when it was put away. As above, start with the easy stuff.

Did you do anything to the bike before putting it away that may have created a problem? For example, if you pressure washed the bike, water may have entered the ignition switch, plug caps, kill switch, or kickstand safety switch. A spritz of WD-40 or some other moisture-displacing lubricant may solve the problem.

Is there fuel in the tank? Sure, you know there's plenty in there, but play it safe, pop the cap, and take a look. If you can't see it sloshing around, the tank might be empty after all. Of course, on bikes with underseat tanks and remote filler caps, this check won't be possible. If the bike has a petcock, place it in the reserve or prime position and try starting the bike. Still won't start? The two most likely suspects: Either fuel isn't reaching the engine (assuming the tank is full), or you've lost the spark.

If the bike shows no inclination to start, I'd head for the spark plugs. If the bike coughs and sputters, I'd lean toward the fuel delivery side. But don't forget, fouled spark plugs will certainly make a bike hard or impossible to start and may mimic a fuel delivery problem. Since I'm pretty lazy, I always check the easiest thing to reach first.

Clean fuel draining out a motorcycle float bowl.
Check your float bowl drain for a clog. If no clean fuel runs out when disconnected, you’ve got a blockage.Motorcycle Cruiser

Clogged Motorcycle Carburetor And Fuel Lines

Loosen the float-bowl drain screw and allow some of the fuel to run out. If possible, catch it in a small container. If there is water in the fuel, it will appear as globules. If water or lots of dirt is evident, drain the float bowls completely and allow them to refill before trying to start the bike. If the float bowls are dry or there is little fuel in them, the problem most likely lies in the fuel delivery system.

If the bike has a vacuum-operated petcock, turn it to prime. If fuel starts to flow, the problem lies in either the petcock or the vacuum line; a little detective work should pinpoint which. If the petcock is manual, move the lever to reserve. If fuel flows, you're either low on fuel after all, or the petcock main feed is plugged or damaged. If no fuel flows, remove the fuel line at the petcock and try everything again. If fuel flows from the petcock but doesn't reach the float bowl, the problem is most likely a plugged fuel filter or line.

Motorcycle fuel pump priming, showing no signs of blockages or fuel pump failure.
With the discharge line disconnected and the key on, the pump should push fuel.Motorcycle Cruiser

Some motorcycles, primarily those using remote fuel tanks or fuel injection, use an electric fuel pump. Testing procedures for these vary, so you'll need to refer to the shop manual for the correct method, but as a rule of thumb, you can test the pump by one of two methods. Start by disconnecting the fuel line from the carburetor or injector. Place the open end of the line in a container and turn the key on. Fuel should gush out of the line. Some pumps are only activated when the engine is cranking or running.

Motorcycle fuel pump that moves fuel from the gas tank to the carburetor or electronic fuel-injection system.
To check fuel flow when a remote tank/pump is used, locate the fuel pump. This one is located under the side cover. Remove the discharge side hose—that's the one from the pump to the carburetor.Motorcycle Cruiser

If the first test didn't produce any results, try cranking the bike for a few seconds to see if things change. If neither method produces any results, chances are the fuel filter is plugged, or the pump or the circuit controlling it have failed. If you suspect the pump itself, check the electrical connections and the fuse that feeds it before condemning it.

Inline motorcycle fuel filter.
If the fuel isn’t flowing, maybe there is a blockage in the fuel filter.Motorcycle Cruiser

Motorcycle Fuel Injector Problem

Bear in mind that troubleshooting a fuel-injection system requires some very expensive and specialized equipment. My recommendation here is to tread very lightly—this is a trained technician's territory. No less consideration is safety. FI systems work at extremely high pressures; get in front of a working injector nozzle and you're going to be in a world of hurt.

Injectors rarely fail. It's usually the pump that's the troublemaker. Most FI pumps run for a few seconds whenever the key is turned on to pressurize the system. Get in the habit of listening to yours when the bike is healthy so you know what it should sound like.

If she won't start, take a good listen. Can you hear the pump run? If not, check the pump fuse. As a last resort, try cranking the engine while you spray a very brief burst of carb cleaner into the air intake. If it catches and runs, you know there is some fault in the fuel-injection system. Determining where it lies will most likely call for a trip to your favorite shop.

Motorcycle Spark Plug Problems

To check the spark, remove one plug from the engine. If it's wet with unburned fuel, it's a safe bet the plug is either fouled from too much choke (yes, I know they're not "chokes"!), or you've lost the spark.

If the plug is fouled, give it a thorough cleaning, insert it back into the cap, and lay the plug on the cylinder head or engine case. Make sure there is no spilled fuel in the vicinity. Crank the engine over while observing the plug. There should be a nice fat blue spark crackling from the tip. If there isn't, try a new spark plug, a known good one, before condemning the ignition system.

Testing a spark plug by turning over the engine and checking for a blue spark.
Unlike this one, there should be a big blue spark at the plug when you crank the engine.Motorcycle Cruiser

If no spark is forthcoming, you'll have to decide how involved you want to get in the troubleshooting process. The problem could be as simple as an unplugged or dirty connection, or it could lie in the ignition module or signal generator.

If you have the tools, skills, and inclination to track down the problem, go for it, but for the rest of you, this is another instance where I'd recommend you call the dealer and make a service appointment. Be forewarned that electrical problems on modern bikes can crop up suddenly, and can take some head-scratching to find.

Does Your Motorcycle Have Compression?

If you've got good spark and fuel and she still won't start, you'll need to do either a leak-down or compression test to discern where the problem might lie. In the real world, sudden, overnight losses of compression are rare. However, if the bike has been sitting for any length of time, then all bets are off.

If you don't have the proper test equipment, a quick and dirty test is to hold your thumb or finger over the spark-plug hole and crank the engine. If you can feel noticeable pressure, the compression is probably enough to get the engine started. If not, it's time to do a proper check before going any further.

Modern motorcycles are notoriously reliable, but things do go wrong. In my experience, many no-start conditions turn out to be something relatively minor—usually no fuel or a bad connection somewhere that kills the ignition. Remember, engines need a spark, compression, and fuel to run. To get back on the road, all you have to do is figure out which one is missing.

For more articles on how to maintain and modify your motorcycle, see the Tech section.