If you changed the whole shebang, spark plug and coil from say number 1 to number 2, experienced the same results, lowering of rpm and 1 & 3, nothing on 2, compression is within 15% on all three cylinders, then you're not getting fuel to 2, there's a problem with the reeds for that cylinder.
Well $14 for an impellor will likely seem minor in the long run here.....but....toasting the gasket at the adapter plate, head, or somewhere else along the line may be more significant......
