I recently purchased a 2007 HPX 4x4 with the 620cc Kawasaki gasoline engine. It had 186 hours on it and ran great for about 5 hours before losing half its power. I soon realized that the front cylinder was not firing. I checked the compression and it is fine. I swapped the plug with a new one and still nothing. It appears to spark, but I was told by a mechanic that that is no indication it actually will fire under stress. He suggested I change out the coil on that cylinder (as you know there is a coil for each of the cylinders). I changed it with a new coil and still it won't fire (so much for the $80 I spent on a new coil). It appears to be getting gas because after driving it around a while (at half power - the back cylinder runs like a champ) and when I pull the plug it is wet. I'm at a loss for what else could be going on. Any help would be greatly appreciated - thanks, Ryan