Welcome to the seadoo forum blonide92xp. It is very possible that the battery has 12 volts when testing it but could have a bad cell or 2. You need to have it LOAD tested. most auto parts stores will do it for free, like Auto Zone for instance. Check to be sure the cables are clean and getting a good connection from the battery to the -Ground on the engine by the starter and the terminals on the battery itself. Have you done a compression test also. that is an older model seadoo and it might need some TLC. The load of the water on the impeller in the water might be enough to keep it from tuning over and firing up. There isn't any load on it sitting on the trailer it just free spins. Give the compression a check, here is some information;
You'll need a compression tester. Go to Auto Zone. I think they sell for like $25.00. The compression gage, will screw in the cylinder head in place of the spark plugs. To test compression, remove both spark plugs. Place spark plug caps on the plug cap studs near the cylinder head to ground the empty caps. This completes the circuit of the ignition electrical system and prevents any electrical problems from the caps being un grounded. Using the correct adapter for the threaded end of the tester,( same length of the spark plug threads length)Screw in the tester in one plug hole. Hold the throttle wide open. Push the start button. Watch the compression guage, when it peaks out at the most compression, let go the start button. Read the psi number. I would do it 3 times to be sure it is accurate. Check both cylinders the same way. The ideal compression is 150 psi per cylinder. If it is less, it's not a problem as long as they are close to being the same. If the psi is less than 90 it might need be time for a tear down and a rebuild. If the psi in 1 cylinder is say 140 psi and the other is 80 psi you need to tear down and repair. This difference is a lot and there is a problem. I hope this helps you.
Do you have a seadoo shop manual? Here is an idea for you also to think about. This could save you a lot of money in the long run. You could join as a "premium member". As a premium member you can down load a authentic seadoo manual from the seadoo manual library. In the library is a variety of manuals for almost all years and models. You can view as many as you like on line as a PDF file, or download it and print it for your personal and privet use. There are operator manuals and repair manuals for you to do your own repairs on your seadoo. The repair manuals have everything from troubleshooting, repair procedures to winterizing. It contains wire diagrams torque specs and pictures for disassemble and assemble instructions. In the spec sheets it tells everything needed to maintain oil changes, spark plug gaps, carburetor rebuilds and impeller wear ring tolerances. Click on the "Seadoo Manuals" link at the top of the page for more details. If you need any help or get in a jam, we are always here to answer your questions too. Premium members get priority when it comes to getting quick detailed answers.
Keep us posted on your progress, we're here to help.
Karl
I don't think it likes the water...I hope I'm wrong!
