My dad has a Husqvarna WH5219 walk behind with a 19 horse twin Kawasaki FH580V. The mower ran fine until one day the blades wouldn't engage all the way. I checked all the spindles, belts, etc, but it wasn't that. Instead I find out that the motor is only running on one cylinder, because I pulled each plug while the engine was running, and on the first one it shut off, but on the other one the motor stayed running and didn't affect the motor. So I replaced the plug, and that didn't work, so I took it out and plug didn't feel anywhere near as hot as it should of after running for a couple minutes. So I'm 99% sure it's the coil, but I thought I would ask here first though and see what you guys think before spending $50 to get a new one. All answers are appreciated.