no spark
check the harness from the magneto, that is the pick up that tell the engine when to spark.....(timing). if your magneto has developed rust or the harness connection at the magneto(front of your engine should be a wiring harness)is loose ....no spark.... ... I assume it turns over and no spark.
sooooo.....you should also check all the connections to the coil...if you follow your spark plug wires back to the "box" they will lead you directly to the coil. since these are creatures of water, corrosion is the enemy. Also they vibrate alot so things get loose. You can pull the coil and have it tested. the guys here at the forum are very knowlegeable. If you give the right information you'll get the right information. Did you ground your spark plug to test it? if you don't you can damage stuff(coils etc) and it may not spark, you can ground against the engine. That is why your engine has a place to put your spark plug wires when you disconnect them. Hope this helps. I have two sea doos, love them.... but I used to work on airplanes.