Yanmar 20GM fuel consumption
- Thread starter mellis18
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For my Yanmar 2GM20F on our H-33.5 with a 16 x 11 prop, the fuel consumption is 0.35 GPH with a new mixing elbow, and 0.45+ GPH when the mixing elbow needs replacing. This is based on careful records of engine hours and fuel usage (taken on) during each season - over a 12 season period.
You should be running your engine at a min. of 2500 rpm and a max around 3000 rpm when cruising. Your speed is going to be dependent on current, wind and sea conditions.
If cruising at these normal RPM ranges you should figure approx .5 - .75 gph. This will also depend on the prop and the condition of the bottom.
If cruising at these normal RPM ranges you should figure approx .5 - .75 gph. This will also depend on the prop and the condition of the bottom.
I have been charting my fuel consumption for ten years, and have averaged .39 gal per hour over that time, but agree with Navigator 97 above. I cruise at 2800-3000 rpm. I have also been doing a LOT of research on this engine, and have discovered there is absolutely nothing wrong with cruising at 3400 rpm according to Yanmar, but my local dealer says 3200 is probably better for long term wear. Google "performance curves" on the web to find the graphs from the manual; they include a fuel consumption graph/rpms, and it is pretty accurate for well tuned engines, clean bottoms, and correctly matched props.
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