Re: 9.8HP Tohatsu 2-stroke odd behaviour
Unless you have a rather severe air leak, it sounds like a restriction in your high speed jetting or, maybe some restriction in the float bowl valve. Other possibilities, dirty fuel filter(s), faulty fuel pump, tank not venting properly, kink in a fuel line, & so on.
Before taking the carb off, try dropping the float bowl, turn on the fuel & "tickle" the float
up & down, possibly flushing out any debris in the valve. Did this on my generator a while back & it saved me from having to remove the carb.
It has been my experience with electronic ignitions, barring loose/dirty connections, that they either work or die, not much in between.