I've got a Kawasaki FS541V AS07 R. A few weeks ago, the engine was constantly surging at high RPMs. I discovered that the muffler was cracked on both sides so after a small welding job we were back in action. Now its surging at low RPMs and a closer look revealed that I'm only running on one cylinder. I checked for spark on the the weak cylinder and had no spark. I removed the coil and cleaned the rust off of it and the magneto as well. I replaced it and put it back to the factory gap specs with a feeler guage. I have spark now but its very weak. I've rechecked the gap and everything. Does this mean that I have a bad coil? The other cylinder has great spark and the engine runs fine on that one cylinder its just weak when the blades are engaged. I'm assuming I have a bad coil but in the interest of saving my company money I wanted to make sure that there isn't anything else I should check before I start buying parts to resolve the issue.