I have a 1999 Yamaha 200 (3.1) fuel injected. When I leave the boat ramp and have run approximatley 1 mile reaching 5800 rpm, the motor will feel like it is missing and loose 100 rpms for 2-3 seconds and then go back to 5800. It only does this once, after that it runs great the rest of the day.The plugs and fuel filter are new, I run Chevron 93 octane with Yamaha ring free in every gallon every time. I have had O2 sensor problems before and this seems to be one except it only does for 2-3 seconds then clears up and doesn't do again that day. It doesn't do it everytime I go out either but it does seem to do it more often it colder wheather. I just want try and be sure it is not something else before I buy a sensor.
