"No, not always. This has a Pr
"No, not always. This has a Prestolite ignition system. You will have 2 CDI packs that fire the 4 coils (2 coils per pack).
There is a diode in the CDI packs which effectively split it into 2 separate units (inside). So half of the CDI pack can go bad which would look the same as one bad coil. This can be checked easily by disconnecting the ground wire from that pack (it goes from the pack over the top of the motor, under the flywheel to a terminal strip on the other side of the powerhead). If you disconnect that ground and you get spark back, it is the pack that is bad, however that is not a work around. Without the ground connected there is no way to shut the motor down other than choking it out or running it out of gas.
It can be a bit confusing but lets see if I can give you some hints...
If you have NO spark on two plugs (but must be paired ie 1 and 2 or 3 and 4, but not 1 and 3 as an example) that would indicate a bad pack
If you have no spark on 1 plug it could be either a bad coil or a bad pack or a bad trigger (sensor).
No spark on any plug would most likely be a bad stator, but could be two blown packs.
These can be quite a pain to troubleshoot, but you don't want to go swapping out parts to try and find what is wrong. Those CDI packs sell for over 400 bucks a piece from Merc (although you can get them for half that in the aftermarket and even cheaper used - but used is always a gamble).
If your spark is intermittent - ie. sometimes it's fine but then it will miss, that is almost always the trigger (sensor).
Additionally, the wiring on these is pretty poor so check the main terminal strip (below the packs) to make sure everything is connected. The ends tend to bust off, particulary on the trigger wires (the 8 little wires on the far right of the strip)...
Hope this makes sense and helps a bit, I have spent many an hour chasing my tail with prestolite ignitions..."