[Duffman]

By plunger are you talking about the oil dipstick? and where did the oil pour? Under the engine cowl and all over the powerhead?

If thats the case, mop up what you can with rags, then shoot some brake clean on the oily surfaces and dry with compressed air. The acetone in the brake clean will help evaporate the oily film. Just be careful, the brake clean will remove paint.

You want that oil off all rubber parts, it will deteriorate them over time.