Can someone explain how the electrothermal fuel enrichment valve operates on my '02 90 hp yamaha 2 stroke? I rebuilt the carbs, and it made me curious as to how the enrichment system operates. The test procedure stated to supply 12 volts for several minutes and measure valve movement. I was under the impression that this helped with cold starts, as well as during the warm-up period, but I'm puzzled. Thanks.
