You said you changed the oil, so I hope you also changed the oil filter??? Any chance you put the filter in backward??? Also, check your compression. You might have gotten a defective ring. The bike is on warranty for a year, so make it the dealers problem.

No way this is caused by poor quality oil! I would continue to run GN4 for the breakin period (at least 10 hrs.), then swithch to Honda HP4 Synth/Petrolium Blend (or if you insist Maxima Ultra full synth) after that. Good article on engine oil-
http://www.thumperfaq.com/oil.htm