Do you notice in the forums it is always the polaris's with electrical problems. Thats because their electrical systems are terrible, even worse than seadoo. If it weak spark (test this with plugs still in engine to load it up and with another spark plug to a head bolt), it will either be the the high tension leads, plug caps or charge coil. Also check wiring loom and box for any traces of water corrosion. If it has no spark at all and all the wiring is in good condition it is likely to be a lighting coil, main coils or the CDI. The lighting coil ohm figures and wire colours should be somewhere on the net.