2007-2010 Kawasaki Ultra 250X/260X/260LX PWC Factory Service Manual, Page 84Get this manual

FUEL SYSTEM (OFI) 3-25 Troubleshooting the OFI System
Poor running or no power at high speed

spark plug loose (tighten it)spark plug dirty, broken, or gap maladjusted (remedy it)spark plug incorrect (replace it)knocking (fuel poor quality or incorrect)engine overheatingengine oil level too highengine oil viscosity too highother:

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives