I have a 1999 Yamaha xl1200 waverunner that's sat

Not a problem if 1 drops below 60 issues will start. Put 5 oz of marvel mystery oil in the cylinder to help free up the rings. Pour in turn over engine do not start. Let sit over night.

Check this site to see if they have the service manual you are looking for.

https://www.manualslib.com/

hi there could be corrosion on the switch gear and kill switch check and clean as well as the wires going tostarter soliniod,corrosion on these electrical connections are always a problem cheers pete

U may have the wrong starter or it requires shims ( spacers) to adjust proper clearence.did u possibly drop or not see them when takin out?

Hi, most likely cause and the easiest to check is exhaust leaking in the engine compartment. Run it without the seat fitted for the same time frame and if it fixes your problem you are looking for an exhaust leak. Regards Phil.

https://www.jetdrift.com/yamaha-waverunner-3-650-review/

Gas oil mix 50-1

Sounds like the carbs are gummed up from the old gas sitting in them. Remove the carbs, disassemble, clean with a carb cleaner, and reassemble.

i recomend replacing the solinoide !!!

my 1998 xl 1200 has this thing it the batter is changed or if it sits for awhile you have to hit mode then something that says code should pop up on the screen then hit a b c a and then it should be able to start. but your code may be different

Try jumping the waverunner using a set of jumper cables and your vehicle, this will rule out if the battery is bad. If you still have the same issue, check the connections. The connection at the starter or another place may have corroded a bit. Yet another option is to remove your spark plugs to make sure that your motor has not hydraulically locked. Once you have removed the plugs try and turn over the engine. You may need to ground out your plug wires if you have an electronic ignition to protect it. I hope this helps.