I have a Yamaha z200txry . Motor starts and runs fine I have a long idle out to run the boat , no problems 1 hr later im out running at speed 4200 RPM sometimes will fall on its face sometimes will run for hr's . Come off plane and idle for 30-60 secs and almost every time more will through a pulser coil code . i check voltage while running all 6 are at 10 volts even while it has the code and running like crap . On the YDS system while its running poorly it will also drop any cylinder randomly . Im thinking its a bad pulser coil but i don't understand how im still getting voltage out of it . Lost here Have done a run down on the normal thing's running on a key switch at the moto,r portable tank , all filters changed . spark plugs changed even though all looked great , fuel pressure at speed all check out , never had any water in fuel issue . Only other thing is its the older ignition system with the standard plugs .