Hello. I have a 2001 Yamaha F115 4Storke that ran rough and alarmed at 5500-6000 RPM. I changed the thermostat (no help) and then changed 2 bad spark plugs. Under a microscope, one had a hairline crack in the insulator, the other had irregularities in the electrode and you could see where it had...
I have a 2001 Yamaha F115 4 Stroke that starts and runs fine, however lately an alarm has been sounding at high RPM (between 5300-5800). <br />Neither the oil or overtemp indicator go on and the motor continues to run smoothly (although I quickly slow down when the alarm sounds). <br />After...
