Yamaha Waverunners (specifically operated on salt water) occasionally run into some corrosion and battery issues, which is the most common reason why your equipment randomly won’t start. So here’s how to fix it quickly.
If you’re trying to start it and the digital screen is trying to flash and it sounds like it might start: First thing, check the connections of the cable to the battery and make sure the battery isn’t damaged and is secure. (Tip: You can wiggle the cables while trying to start the engine to quickly get it started back up and make it back to your dock.) If it starts while manipulating the cables then you most likely have a corroded or loose connection. You’ll need to clean the terminals and connectors with a wire brush and some battery terminal cleaner to clear the corrosion and make a solid connection.
If once the connections are clean it’s still struggling to start and flashing the digital screen, you may have a bad or dead battery. You can take the battery out and attempt to charge it to see if this fixes the issue, first. You will often here clicking while trying to start if this is the issue.
What Not To Do
DO NOT CHARGE THE BATTERY INSIDE OF THE SKI. This can lead to a build up of fumes and one small spark from the battery connections can ignite it quickly. It’s also important to use the correct amperage charger for your battery.
If charging the battery does not improve it’s likelihood to start, you can have it tested by a local auto/marine shop.
Occasionally on a jet ski or waverunner, you’ll run into issues with the starter being your culprit. You can usually hear the starter hanging up when attempting to start. You can try to manually bang on the starter to loosen it temporarily in stranded on the water situations. Usually, if you’d checked all the other potential issues and you’re still having intermitted or non starting issues than this will be your next part to be considering. If the ski’s digital display is coming on solid and normal but it’s struggling to turn over while starting, than it’s most likely your starter. A mechanic will most likely be needed to replace the starter.
If the engine has been submersed in water and attempted to start with water up over the engine and it’s no longer starting, you may also be hydro locked. In which case, you’ll need to get a mechanic involved soon to clear the water from the engine in order to fix it and avoid corrosion.