2002 900STS Firing Issue
 

first time user but i normally do my own maintenance. I ran into a bit of an issue with the firing of the coils. iam wanting to replace two of three but want to measure the resistance to verify but not sure what they should be?

A little history, i had the jetski running well. would top out around 52-54MPH. We took it out and i let my son put it in the water. we were in a hurry and we forgot to install the two rear plugs. well it began to fill inside the hull after minutes of riding. Salt water of course is not to friendly to parts. I had to move my boat from my boat slip and attach the front of the ski to the hoist so we could drain it. after draining we tried starting and eventually did run but would not run over 25mph. brough it back to the house and checked the plugs by removing one at a time. It would shut down with only one spark plug cable connected. the other two i would remocve and nothing happened.

So after sitting a while i finally had time to troubleshoot and removed the power box cover. Everything inside still looks great. i figured it would of gotten wet during the "sinking". I removed the wiring harness from one of the coils and measured the resistance, it was around .3 ohms. normally i would expect more than that. measured the other two and the same reading. well i was hoping to find two open coils but not three measuring the same since only one was firing while it was running.

Dont know where to go from here. Any guidance would help besides taking it to a repair shop.

Joey

The coil primaries do measure only 0.18 to 0.26 ohms. It is hard to measure such low values, so I assume that your 0.3 ohms is a good coil.
Do NOT pull a plug wire while running. Firing a coil with only "open air" at the end of the wire can generate damaging voltage spikes back into the solid state CDI module and fry the firing transistors. Always ground loose plug wires before cranking the engine. Having said that, sometimes you get lucky and no damage is done.
Are you sure the two plugs are not firing??? Maybe they were just too wet? Maybe you had water contamination in those carbs or crankcases and that's why they didn't provide power. Take fresh plugs, and ground them on the cyl heads and watch for a sharp blue spark while cranking.
Do you think you got water into the engine itself? If so, you must get it running quickly to fully dry it out and prevent rust up. If the e-box was dry inside, I would not think the CDI was damaged from the "sinking". Stator should also have stayed dry if it wasn't fully flooded for an extended time. Exposed stuff (connectors, etc) should dry out fairly quickly.
So, unless you damaged the CDI with loose plug wires, I'm thinking you had wet plugs... hence low power. Get fresh plugs, test their firing, and then get it running. Spray a bit of WD-40, or premix gas down the carbs to test for water tainted fuel.
Good luck!.