I'm no guru nor a "spurt" but your plug looks good to me. I've seen/heard some high throtlle "blips" a few times and they always seemed to be voltage related. Make sure your ignition switch, extensions(adequate guage) and connectors are in good shape and haven't been exposed to extreme heat such as being too close to the muffler/cylinder and degrading (melting) the shielding. Check ignition battery voltage with a loaded voltmeter? Have you tried running the motor with battery plugged directly into the EI and by-passing the switch and extensions to see if the "blip" goes away? If you do by-pass the switch to test, make sure you have an alternative way to shut down the engine!