This engine has the stock animal flywheel (Aluminum) and I beleve I gapped it to stock animal speck but I can check. I also have a damaged coil wire running to the spark plug that has been taped up with elecrical tape, It could be arcing to the block. This coil is the older type without the pvl flywheel and I haven't yet been able to locate a replacement. I also need to check compression just to cover all my bases. I do have another motor I could swap this with temporarily but it to would also need to be tunned since its a less extreme version of this motor built out of a briggs inteck 6hp.