Quick Outboard Motor Troubleshooting Tips

When your outboard fails to start or cuts out when it should be running, the problem is often simple to fix.  

Troubleshooting outboard motor

Here are some quick troubleshooting tips to get your outboard back up and running again.

Outboard Won’t Start

Check the kill switch

Make sure the kill cord switch is firmly in place by removing and reinserting it. If the kill switch fails, disable it by disconnecting the black/yellow striped wire coming from behind it.

Outboard troubleshooting kill switch

Put shifter in neutral 

Many outboards have a built-in safety feature that prevents them from starting unless they’re in neutral. Knock the shifter into gear, then back to neutral to be sure it’s where it needs to be.

Check for fuel in the tank 

Fuel gauges aren’t always accurate, and running out of gas is a lot more common than you might think. Check that there’s fuel in the tank and fill it up if necessary.

Outboard quick troubleshooting fuel

Open the gas tank vent 

If the gas tank has a vent, make sure it’s open. A closed vent prevents air from flowing into the tank and fuel from flowing out to the motor.

Inspect fuel lines 

Check the fuel line from the tank to the outboard. Look for any kinks or pinch points that may be preventing the fuel from flowing through, and straighten out the fuel line.

Check for flooded motor 

If there’s a palpable smell of gas, the engine is probably flooded. Wait for about 5 minutes for the excess fuel to drain and evaporate, and then try starting the outboard again.

Outboard Stalls When Put Into Gear

Clear the prop shaft 

If fishing line or other debris tangles up the prop shaft, eventually it’ll cause enough resistance to kill the motor when it's put into gear. Turn off the engine, then tilt it up and remove anything that’s wrapped around the propeller and/or prop shaft.

Outboard quick troubleshooting tangled propeller

Outboard Stalls When Idling

Check idle air control valve 

If the outboard is fuel injected, its idle speed is controlled by an idle air control (IAC) valve. Replace the IAC valve with a new one.

Outboard troubleshooting tips IAC valve

Outboard Quits Unexpectedly While Running

Check kill switch and fuel 

Check the kill switch, fuel tank and fuel line as outlined in the Outboard Won’t Start section above.

Inspect battery and fuses 

Check that the battery has power and recharge or replace it if necessary. Also check the fuses and replace one if it has blown.

Pro Tournament battery charger

Minn Kota MK2100 battery charger

Minn Kota Precision battery charger

Monitor engine temperature 

If the engine overheats, there may be an automatic system that’ll shut it down. Check if there isn’t a stream of water coming from the tell-tale when you crank the motor, which is a sign the water pump or impeller has probably failed and must be replaced. 

Outboard motor troubleshooting water pump impeller

If you’re not far from the dock, you may be able to limp the boat back by letting the engine cool and running it for a couple of minutes at a time. Otherwise, you’ll need a tow back to the dock.

Check fuel filters 

Drain any water in the fuel/water separator and replace the filter element. Replace the in-line fuel filters, because even small amounts of dirt can clog them.


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