I have a 1991 Yamaha 225 hp and am no longer using the automatic 2 cycle oil mixing. I have disconnected the fuel oil auto mixing unit and have fastened the gage so that it stays in the full position. My yamaha gage on the dash shows the green light for oil is fine or full position. I am pre mixing the oil fuel mixture to a ratio of 50:1. Last year I used the boat two times after doing this and it ran fine and went to full rpm. I have finally been able to use the boat this year but the motor will not exceed 2,000 rpm (except for one time for about 20-30 seconds the boat planed off) which was the initial problem when I disconnected the auto fuel oil unit but overcame that when I secured the gage in the full position and believed I overcame the problem when I test drove it twice last year and had no problems exceeding 2,000 rpm. Can you help me trouble shoot this.
Thank You,
Thank You,