I just purchased a 2004 zx10r and changed and subsequently overfilled the oil with the recommended castrol race oil. The bike has about 5000 miles and ran like a champ prior to my mishap. I removed the approximately 500cc of "extra oil" after a 30 mile ride. Now I have a low rpm hesitation. I then replaced the air filter with a knn filter (the old one wasn't in terrible shape) and replaced the two inner spark plugs (they were not fouled). It has a lot more power in the top end but still hesitates under 2000 rpm. I talked to the local kawi dealer and they suggested sea foam and a good long ride "to clean it out." No change so far from previous description. It smells a little rich but no odor of gas and no leaks of any kind. Is there anything I can do prior to a major shop charge to go through the engine?