when you say skipping, do you mean missing, kinda a hesitation or what exactly? Have you talked to the Honda shop about this? Ok, did you use a high pressure sprayer? Never use high pressure. It isn't necessary to remove even stubborn mud and you can ruin alot of so called sealed bearings and other parts that are ok under normal water pressure, but allow crud to get in with high pressure sprays.
Now how did oil mix with the fuel? I don't quite understand how that happened??? Sounds more like water in the fuel system. Have you completely drained the fuel tank? I would definately drain and make sure all water is out of the system, filters etc.. and replace with fresh clean fuel and give it a try.
good luck.
markc