Yes its a duce dizzy ,can't help with plugs, I've used champion rn11yx or 12Ok so is a Duceiller dizzy then?
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The head has a raise section but I can't see any numbers stamped on it. However I have now Googled the engine no which starts with 901 which indicates it's a hp engine. It's just I ordered plugs from Paddocks for an hp engine and the thread is too big.
Norrie