Outboard Won’t Start: Carb Basics, Flooding, and How to Start a Flooded Motor

In this video we discuss why motors flood, we will disassemble a Mercury 6HP outboard carburetor and review what can cause flooding. Finally we will intentionally flood a motor and walk through how you can quickly unflood and start a flooded motor.

Safety First!
Never start your motor unless it’s in neutral!
Gas is flammable and dangerous, if gas is present kill the motor and all eliminate all heat and spark sources.
Always have a fire extinguisher on your boat.
Always take your motor to a trained mechanic if you don’t understand all the risks and are not trained to do repairs. Motor repairs and flooding can be dangerous.
Starting a flooded motor should only happen if it’s an emergency, it’s best to just let the motor sit and either dry out or just get a tow and take it to a mechanic.
Read your manual!

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WARNING** flooded motors have burnt up cars and boats. They can be dangerous. If gas overflows and hits a hot exhaust it can catch on fire! If you ever see gas dripping or overflowing in your motor, if it is safe to do so kill your motor, close your fuel valve, make sure all heat sources are away from your motor, and assess your situation. You are responsible to assess and safely react to your own situation. Never try to restart a motor that is dripping or overflowing with gas. It is dangerous. These starting procedure are only for minor flooding caused by the motor being flooded due to starting user error or if you need to start it in an emergency. If you have a mechanical issue causing your flooding, DO NOT TRY TO START THE MOTOR. Get to a safe place, assess the situation, and get a trained mechanic to fix the mechanical issue before restarting.

[aquaxious]

Just wanna let you know I’ve been sitting in the middle of the lake for an hour. This video saved my life. Thank you kind sir.

[EandFreyArt]

Sorry to be a downer but there is an easier way to get it running without all of that effort. I am a clammer in Massachusetts and go year round clamming. Even in 10 degrees. I have used a mercury 20 hp 2 and a 4 stroke for 21 years. To prevent flooding, don’t pump the ball ever. If flooded, pull the gas line off and pull the cord and clear the gas. Pull until it fires up then attach the gas hose back on. Simple fix and it has worked on at least a dozen of my friends motors as well.

[koremeltdown]

Funny, you can ‘know’ something but when someone lays it out so well it is really helpful. Nice job on the explanation.

[melrobinson]

Many many thanks
Really appreciated the way you explained everything. Think I am starting to understand the balance of choke to fuel delivery

[jonahcouper]

Mate cheers the help, engine hadn’t been run for months, engine was flooded, did no choke full throttled and the engine turned over first pull. Absolutely unreal 🤙🏾

[vupham]

I’m newer for the motor. Fisrt I can not start my motor for an hour😢. Thanks God when I saw your videos. It’s was started at first pull😮. Thank you 🙏

[lochheadk]

This video was just what I needed. I have an Evinrude 35 and haven't fired it up in over six months. So my wife was watching me get more and more frustrated as I pulled the cord over . . . and over . . . and over, like six thousand times. I finally got so irritated that I pulled up Youtube and found your video. Yep . . . I flooded it! I went back out and per your video, I maxed the throttle and cut the choke. After about 6 more pulls, it fired right up. Thank you for the help!!

[emtzack]

It’s funny. I cleaned out my carburetor the other day after letting my boat sit. I couldn’t find a spare gasket, and noticed that the motor was running great, but fuel was spitting out of the sides of the fuel bowl seal on my carburetor. I ordered a rebuild kit, and the gasket fit fine, but I noticed the other parts were a little weird. I put a new float in the carburetor and a new gasket and noticed that it was venting fuel out of the top fuel vent and the motor flooded. I had a feeling it was the new float causing the issue. This video confirmed that, and I switched the old float and needle out and it started the first pull. Two lessons learned tonight: if it’s a good deal on Amazon, it may not be the best quality. And if it doesn’t need to be replaced, don’t go and replace it. Shame on me for not running my boat for over a year!!!!

[gerardovillarreal]

Super helpful video. My outboard flooded. I maximized the throttle and let airflow through the choke. Disconected the gas. And turned on after 2nd pull. Subscribed and liked.

[kodywynn]

This video is a life saver. My 3 days old outboard shutdown and won't start. I followed the troubleshooting in this video and it started in a few cranks. Wish I found this earlier. My other motor is identical and is only 40 days old with the same issue. The dealer wasn't able to help and I had to get another one for my trip.

[daves]

Been banging my head against the garage. Drove around for 2 hours, took outboard off the boat and layed down correctly for drive home. Once home couldn't get started again for an hour. 0 choke, max thottle, started in 1 pull. Thank you thank you thank you!

[markkobel]

Thank you so much for this video! It saved me from my own stupidity. I had started the motor with no problem, then as I was still at the dock it quit! Spent 40 minutes trying to restart but it wasn't getting gas. I unknowingly had pulled the emergency fuel shutoff lanyard engaging the fuel shut off. You mentioned the emergency shutoff in your video and I knew right then what had happened. I went and reconnected the clip and wallah, motor started and ran great!

[captainAltan]

hey thanks i will use on my 4 hp 4 stroke hangkai which fill up is a mess on the go lots of love!

[kensJAMZ]

This saved me on the waters. I simply just trolled for 2 hours and let it dry out. Primed it firm, put throttle just a bit half way, and the motor started up like a champ. Thanks for the tip! I have a 6 cylinder so pulling tjose spark plugs out one by one would've been a bit of a hassle.

[fjbsuln]

Great video. Your common sense approach and the tips are great and will help a lot of boaters and fishers. Much appreciated.

[akiramiyazono]

Dude you are the best, my honda metropolitan laid on its side for like an hour and I know it's flooded but I don't know about carburetors. This helped me understand what's up.

[alvinpate]

Thanks, This was very helpful with determining and fixing my flooding problem problem.

[jdelbo]

So relieved to find this video. Too bad I found it after absolutely obliterating my shoulder trying to start my outboard for the first time, yesterday.

[medievaljon]

well here I was worried it maybe wasn't getting enough fuel... now convinced I had flooded it. letting it try out, I have two sore shoulders from attempting to get it to go. Exact same motor. I think fuel tank out in sun may have expanded and flooded it started part of the issue. hopefully can get it going

[Capt-Adventure]

Your tips really work on my Rescue Boat engine. Thank you so much.