Its not sounding good Fontyyy, from vast exsperiance i think you will of spun a ring maybe. This colours plug a very grey/tan. with low comp on one cylinder it will start but not easly and will normaly not tick over.

a needle floating up as you say will only cause it to go rich and wont of caused this... take your chambers off and have a look up the exhaust.
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If I have to take the carbs off once more...