Power isn't the only thing that goes up on bigger bikes. The overall weight and distribution is something that people often forget to take into consideration. This will have an impact on your cornering.
You said you drove a 125 for a year and then went on to this? Thats a big jump and you probably weren't prepared for it. Keep us informed.
1999-2000: Aprilia RS 50, 2000-2000: Suzuki TS 50, 2001-2002: Kawasaki KMX 200, 2002-2006: Yamaha Virago 250, 2007-2009: Yamaha Virago XV 535, 2009-2012: Suzuki GZ 250 Marauder, 2012-present: Kawasaki ZZR 600
"Green is better, I need green!" ~ Max my 2 year old