I have an Artic Cat 98' Panther DELUXE 550, 2 up. Both cylinders are fine, they are not chipped, rings are fine, pistons are fine, and so are the rods. There is spark to both sides on the wires, both plugs have sparks, there is gas to both sides. The CD box is fine, all gasket in the engine and around are fine. Checked the plug under the engine that shows it is fine. Compression test came out fine. Tried the timing, clutch. However it runs, but runs on one cylinder. One cylinder has been re-maned, the one that hasn't is cold when it runs, and has no spark. However I have done everything possible to see what is going on and can't find the problem. Even the techs have given ideas and they have been done already and that is not the issue. I have even retried what they have suggested and still find that is not the issue. I am running out of ideas, there is spark, gas, but it will not run. It was rode for 4-5 hours trailered back home, sprayed off, stuttered and sputtered after that. Pulled it apart to let dry for the night in a heated garage. Put it back together trailered it to a spot to ride, and it wouldn't work. If you have any ideas please help, last thing to do is pull it apart for the shaft. Really do not want to try that, any suggestions would be great.