1993 Yamaha 225 anti knock sensor

[Terry Harper]

My 93 225 carb model V6 travels about 1 mile at 4000 rpm when the anti knock sensor causes the computer to wind the timing back 5 deg.resulting in a loss of revs & power. Fitment of a $400Aus new sensor had no effect whereas simply removing the wire seems to solve the problem.Using premium grade fuel seems to minimise its occurence but does not eliminate it. Local yamaha mechanic cant even get any info from national service manager. My dilemma is, do i simply cut the wire &forget about it or am I risking serious damage to the powerhead ,or could there be another problem causing the sensor to register.