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Reasons Why Your Jet Ski Won’t Start

It can be very frustrating when you go out to hop on your Jet Ski and find out that it won’t start. I’ve created a list of the most common reasons why your Jet Ski won’t start and what you can do to fix the issue.

WARNING! Batteries and the starting system of your jet ski carry HIGH ELECTRICAL CURRENTS, which can hurt or seriously harm you if you don’t know what you’re doing. If you don’t know what you’re doing, please have your local dealer look at it for you.

Dead Battery

Random jet ski batteries that are dead

Having a Dead Battery is usually the biggest reason why your Seadoo, Yamaha, or Kawasaki jet ski won’t start.

8 out 10 times, it’s the battery. Even if you charged the battery or it’s a new battery, it still can be the battery causing the jet ski to not start. Even if you think the battery is good, check the battery. We talk more below about how to check the battery. 

  • If you put the key on and nothing happens then, the battery is completely shot and needs to be replaced.
  • If you put the key on and the display turns on, but when you press the start button, and all you hear is clicking that means the battery is weak. A weak battery will need to be charged.

You may also like this post: REASONS WHY YOUR JET SKI BATTERY DIES

To charge a battery, you want to use a smart battery charger (Amazon Link Ad) that does not exceed 2 amps. Also, you need to let the battery charge for hours, or overnight to get it to be fully charged. To keep the battery from dying all the time I highly suggest getting a Solar panel like this one (Amazon Link Ad). Just hang the solar panel off to the side when you’re not using the jet ski.

Sometimes you’ll need a new battery (Amazon Link Ad). Your local dealer can help you find the correct battery for your machine.

One Solid Click or Thud

If you go to start your watercraft and all you get is ONE solid click or thud, then the Starter Relay (Amazon Link Ad) has gone bad. Also, you know the starter relay is bad is when you press the start button multiple times before the jet ski will finally start.

I have even had customers tell me the procedure to start their watercraft, like waiting for the dash to turn off, then you press the start button 11 times while tapping the handlebars 4 times before it will start. There is no special procedure for starting a jet ski, and if you have to do something very similar, you need a new starter relay.

The starter relay is the device that sends the power from the battery to the starter motor to turn the engine on. The way you determine if the starter relay is bad or if the battery is bad is by the clicks. A bad battery will cause the starter relay to make multiple quick clicks, while a bad relay will do only one click when you press the start button.

Your local dealer will more than likely have Starter Relays in stock. For some model Jet Ski’s, I highly recommend letting the dealer install them as some can be very painful to install. It’s only a couple of wires, but the location of the relay can be very difficult to get to, and having the dealer do it could be worth it.

Battery and Starter Relay are Fine, now what?

If the battery and starter relay seems fine and has passed all test above then, I would check the battery again. There have been plenty of times where the battery charger says the battery is charged and ready to go, but when I put a load tester on the battery, it was a different story.

I would even take the battery to your local dealer or even an auto parts store to have them load test the battery to make sure it’s okay.

If the battery passed the load test, the gauges come on, and the starter relay is good or has been replaced, then you only have a few more options left. The next thing in line is the Starter, and it could have gone bad. It’s not common for the Starter to fail, but the starter relay and battery will fail eventually because of the stress they go through (they’re wear-and-tear items).

If you have gotten to this point, you’ll need to take it to your local dealer. If the problems are beyond the battery and starter relay, then something is going on beyond your control. Your local dealer can hook the machine up to the computer to see what is going on and what needs to be fixed.

Sucked Something Up

It’s rare, but one reason why your jet ski won’t start could be due to you sucking something up. A stick, rock, or even rope can get in there and wedge itself in keeping the pump and also the engine from spinning over.

I go into more detail about this here. Usually, when you suck something up, you notice it, but maybe a friend returns the machine and doesn’t tell you about it, and this would lead you to this conclusion.

Sum Up Jet Ski Won’t Start

  • Why your jet ski won’t start can be a bad or weak battery, bad starter relay, bad starter motor, or you sucked something up.
  • 8/10 times a jet ski won’t start is due to a weak battery or bad starter relay.
  • In rare occasions, the key or other electronic parts could be the reason why your jet ski won’t start.
  • If your jet ski clicks once when you hit the start button then it’s more than likely the starter relay.
  • If you have to press the start button multiple times or put the key on and off before the jet ski starts then it’s a bad starter relay.
  • If your jet ski clicks multiple times when you hit the start button then it’s a weak or dead battery.
  • If you’ve put a new battery in your jet ski and it still won’t start then it could be that the new battery is dead and needs to be load tested.
  • Never go off on what a voltmeter says but instead what a load tester says when checking if a battery is good or not. You can get load testers at many stores but most auto parts stores will have a load tester you can use for free.
  • If your new battery load test fine and the watercraft still won’t start then it could be bad grounds or other electrical issues.

201 thoughts on “Reasons Why Your Jet Ski Won’t Start”

  1. Hey Steve just a quick question , I have a 1994 Polaris Sl 900, It has been sitting for about 3yrs and has not been started since then. It worked just fine before but I recently tried to start it ,but will not turn over , I tried turning the shaft by hand but it seems like the motor is locked, could this happen? or maybe battery ?

    Reply
    • Yea, if the engine sits for years and was not fogged then rust can form and lock the engine. It’s best to do storage procedure before storing a jet ski for a long time. To get it fix might require a teardown, but I would drop it off at a local repair shop to see what they say.

      Reply
  2. hey i have a 1997 kawasaki 750 zxi i know the battery is bad but i got this jet ski from a family member that could not get it to run and i dont want to sink a lot of money in it so what im asking will it get enough power thru jumping it off with my truck to make it start it cranks great but no fire to plugs no lights on the panel btu the fuel gauge works and it has plenty of oil i just want to hear it start before i replace the battery

    Reply
    • Never jump a jet ski battery with a car or truck, you’ll fry the electronics. The only options you have is let the battery try to charge or buy a new battery. It’s best to let a repair shop look at it since you may have electrical issues if no lights come on.

      Reply
  3. 1999 yamaha 3 cylinder charged for couple hours and go to start I get the word start on dash and it makes a weird buzzing noise when I hit start. Battery bad? Please help thanks

    Reply
    • Buzzing could be a messed up relay, either starter or a smaller one in the electronics box. It’s best to let a repair shop look at it.

      Reply
  4. I have a 1998 seadoo gts jet ski. It will not start. I replaced the battery due to it being junk. Then replaced spark plugs. Still would not start but would crank. If you put starting fluid or gas in carb it will run. So I blew threw all glass lines and vacuum hoses. And checked all hoses for leaks. I Found no file going to carb due to lack of vacuum. So I rebuilt the carb. And it ran for about 30 seconds then stopped. So I tried to start it again with starting fluid and it started up but died any ideas?

    Reply
  5. Hi Steve. I have 2003 sea doo 4 Tec. Got it used. The guy I bought it from said the starter relay was going bad, so I changed it. It ran great all morning, then after sitting on the beach for a couple of hours, I turned the battery on to go home and it tried to start itself. After wiggling the wires around, it started normally. Then when i started going and bouncing, it would cut out again. After about 10 min of idling, I had to get back to the dock, it ran perfectly again. I cannot find any loose wires. Have you ever seen this?

    Reply
    • You said you turn the battery on, this must mean you have a battery switch. Jet skis don’t come with battery switches and it’s not the best to have them because they create an unneeded load between the battery and the starter. This could be your issue as you have too much going on between the battery – starter relay – start motor because of a battery switch. But if someone put a battery switch on a jet ski then it must mean it was draining the battery and you could have an ECM problem. Don’t forget to check the obvious stuff like the battery’s condition and if the connections are tight. If anything it would be best to let a dealership look at it.

      Reply
  6. Hello Steve. My daughter and her boyfriend were riding my 2016 Yamaha V1 sport this past weekend. The ski was running great when all the sudden it beeped 4 times, the warning light came on, then it went completely dead. I had to tow them in with my pontoon. I took the ski out of the water and it will not do anything. The gauges do not light up and it doesn’t click when you turn it over. I charged the battery but it still doesn’t do a thing. Got any idea what would make a jet ski completely shut down. It’s a 4 stroke with 12 hours on it. Any help would be appreciated.

    Reply
    • That is very odd. Since it so new I would take to the dealership and see what is going before messing with it just in case it’s a warranty item. The only thing I would maybe check is to see if the battery connections are tight. I’ve seen loose battery terminals stop a jet ski and throw odd codes before.

      Reply
  7. Any idea where the rectifier is located and the best test method in checking it? There are any marine shops near me or I would take it in for diagnosis. Thank you again!

    Reply
    • The easiest way to test if the rectifier is bad is with a volt meter. I don’t recommend doing this unless you have some experience with a volt meter and working on engines before. With the jet ski out of the water turn it on and measure the voltage of the battery while it runs. After firing up the battery should be charging around 14 volts. If the battery is at 12 volts or lower then this tells us something is wrong the charging system, it could be rectifier or stator or wiring or electronics. Remember you can only run the jet ski out of the water for about 30 seconds.

      Reply
  8. I have a 1996 Tiger Shark 900 Monte Carlo that hasn’t been started in several years. With a hot battery it will not crank over at all. Only makes one single click. Changed starter solenoid and got the same results. The engine rolls over when I turn the drive shaft so it is not seized. Could it be the starter relay and if so where is it located? Any help would be greatly appreciated.

    Reply
    • It’s not often that someone talks about a Tiger Shark. I think it might be your starter motor that is bad if the engine moves freely, the clicking could be the starter motor just giving up. Make sure the wiring going to the starter motor is good and tight and not corroded, the jet ski is 21 years old so there could be other issues too.

      Reply
  9. Thanks for all the time you put into helping others. This thread is great. Bought a pair of 2013 Kawasaki STX-15Fs last summer. Love them, BUT, one keeps losing charge. Replaced the mis-sized small battery with correct size and it made it 3 weekends, but now, when I go to start, I get one click, then several smaller ‘clicks, but nothing else. Display does not show the battery low, as in previous instances. 3rd time with this happening, and on the first two, I towed back to trailer with 2nd ski and got water in motor(question/topic for a different day). Any ideas? Starter Relay? Rectifier? Other? Thanks again!!!

    Reply
    • This is a tough one, I recommend letting a dealership look at it. But if I had to guess I would say the rectifier is bad and draining the battery when it runs?

      Reply
  10. Have a 2011 gti. When you turn off engine something keeps running. Sometimes when you attach the key and start then turn off it quits. Other times need to disconnect the battery. Sometimes it won’t start at all and you have to disconnect and reconnect the battery then it will start.

    Reply
    • That is odd, never heard of this one. It would be best to take it to the dealership and let them look at it. I can only guess that maybe it’s the fuel pump still running which is not good at all.

      Reply
  11. Hello sir, from reading you page and your replies i’m certain all i need is a starter relay, however i figured i’d still ask. Last week ski would try to start over, sounded like starter was hitting, PTO would rock back and forth, charged the battery a bit and she fired right of. This week launched the ski and went to start, nothing, not a sound, not a click, nadda. Brought it home boosted battery, now when i plug the safety switch in, i can hear the fuel pump prime, but when i press start, she gives me one solid hard click from the relay. Then she’ll do it again and again all while depressing the start button. But she will not fire off. Before reading this i was preparing myself for a starter replacement. Thoughts?

    Reply
    • I would start with the starter relay first and then replace the battery. If that doesn’t fix it then you need to take it to a repair shop to let them look at it.

      Reply
  12. Steve, i have 2004 SeaDoo RXP. These past two days, it starts, runs great for about 90 minutes or so then dies, like you pulled the lanyard. There are no beeps that would indicate the key is in place.. try and try and try no power. I tow it back in, get it back home an hour or two later, put the key on and she will start like nothing happened… This has happened back to back days. Any suggestions.

    Reply
    • It would be best to take it to a dealership to let them look at it. Sounds like a bad key or DESS post or ECM but it could also be many things.

      Reply
  13. I have a 1996 seadoo gti new motor ,new battery ,new starter relay . Press start buttons gauge lights up the four red lights come on for the battery ,temp,gas and oil then go off no beep .low gas stays on I have 2 gallons in the machine . Plug my dess key in still no beeps seadoo won’t start ?

    Reply
    • Your ski has a lot going on. To be fair it is over 20 years old and things not working will be common. So many things to try, but maybe it’s the DESS post that is bad? Just hard to tell on a ski this old, it would be best to take it to a shop that still works on 2 strokes.

      Reply
  14. I have 2015 GTX is limited 260 and when I push starter button nothing happens. Dash won’t light up. When u attach key… same thing. Battery has been tested and shows it’s ok.

    Reply
    • I would try a new battery, I’ve had batteries “test fine” but actually was bad. On that model, you should be able to press the start button first and the gauges power up and then put the key on. If that doesn’t happen and you put a new battery in it then the next step is to take it to the shop. I would take it to the shop anyways, the battery in that model is hard to get out.

      Reply
  15. Hi Steve I have a seadoo gtx 4-tec that won’t start properly it turns over and try’s to fire revs to about 350rpm but then cuts off. Reading all your other comments sounds to me like it could be the starter relay just wondering if you had any other thoughts? Many thanks great site

    Reply
    • If it’s turning over then it’s not the starter relay. The way you tell if it’s a bad starter relay is if it doesn’t turn over at all or just make one click. If it’s turning over then it would either be a bad battery or starter motor. It could be even a bad ECM not telling it to fire off. The best thing to do is take it to a repair shop and let them look at it.

      Reply
  16. I have an rxt xrs 2014 Yesterday he first started beeping and it says low voltage it ran 3 or 4times after that and now he wont start the engine Light is on when i hit the start button it jus makes 2 clicks and wont start? I would apricate any help

    Reply
  17. I have a 2008 STX 15f. I replaced the battery so it’s not a battery issue. When I click the green start button, I hear a click but the starter doesn’t turn the engine over. I tried jumping the 2 terminals with large red wires at the rear of the ski – is that the starter relay or something. Anyway doing that didn’t do anything. It didn’t even make the click like you do when you press the green button. Any ideas? Thanks!

    Reply
    • Yes, those two big terminals with red wires is the high power side of the starter relay, avoid jumping those two points as its dangerous. Even if it’s a new battery I would still check that by taking it to an auto parts store and let them do a load test on it. I’ve seen new batteries go bad out of the box before. If that’s not it then it’s either the starter motor or something keeping the engine from spinning over like it’s hydro-lock, blown, or something is in the pump. It would be best to take it to a repair shop to have them look at it.

      Reply
  18. Hey steve i just bought a 2010 yamaha wave runner vx110 and i changed the oil and spark plugs and i ran water through it using a hose, while it was running i kept reving it and after 5 min of doing that white smoke came from the back than i cut it off and when i tried to start it, it wouldnt evn turn and i doubt its the battery because i was using a booster box to jump them. Any thoughts of what the problem could be?

    Reply
    • From you saying you ran it on the hose makes me think you hydro-locked it. There are special procedures to follow when running a jet ski on a hose that you must follow or the engine get’s hydro-locked. It’s best to take it to a dealer or a repair shop to have them look at it.

      Reply
  19. Hi!! I have a Polaris JetSki We just replaced the battery.. and when we go to start it it sounds like it wants to start but won’t.. but when we hook it up to a battery charger it starts right up and will run until we shut it down.. then we have to repeat with the battery charger…any ideas?

    Reply

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