Put some degreaser on the engine and let it sit for 10-minutes. Stuff a rag in your airbox and avoid spraying around it. I think I use the green tip nozzle and don't spray too close. As snopro31 said let it dry in the sun. I fire mine up after the sun dries it, then fog, and grease her up. A good grease job is important because of the hi water pressure might/will wash grease away. Grease all fittings until no water comes out and you see new grease. That has worked for me very well. I spray the whole engine down with a chemical, oil based, that prevents corrosion. Its 711 and comes in a gold labeled can.
No need to pull the engine unless you're bored and looking at possibly breaking something. :no: