Good technique capt. I kinda did the same but just cleaned more stuff fromt eh spark it had like this black carbon style junk cleaned it with a bit of clean gas and air and bingo super clean..

I switched the battery on my iginiton to a 6volt 11mah and the engine stopped giving me that problem it had..

But now it has another.. after a flight when you land and you start to turnt he engine dies in idle... i have checked the idle in the floor taking off the cowling and the idle is so low you can practically see the prop barely stop before going again.. you can advance the throttle to full with no hesitation and lower it back to idle and it can be on idle for 1-2 min a sudden burst and idle again and it won't die..

yet after again another flight as soon as it's lost its forward momentum and you turn to bring it back to the pits.. Boom again dead.. you walk to it flip the prop and on the 2nd one its again on.. moves closer to the pits [about um 40 feet from you again] and boom engine dies again...

I installed a brand new 3004 servo for the throttle.. to take out the guess of maybe a servo glitch.. what could be doing this?