I ran my Seadoo for the first time this year and it ran great for about 15 minutes and then It started running slow and woring really hard. I figured out it was a ignition problem by pulling off the back spark plug wire and putting it on the grounding cap. It turns over but doesnt fire the piston. The front fires but not the back piston. once in a while it will fire but very rarely. I guess my question is this. Could it be the PTO coil?