Irwin 34 Yanmar Reduction Gear Ratio

[Jim Pearson]

I recently purchase a 1982 Irwin 34 Citation SD with a Yanmar 3GMD engine. I am investigating installing a feathering or folding prop and need to know the reduction gear ratio for forward gear. The ID plate from the side of the transmission housing is missing and there are three possiblities from the manual. Does anyone know what the ratio is likely to be?

 

[Ross]

You already know what it is likely to be. To find

what it is put the engine in gear and hand crank the engine with the compression lever open and have someone count turns on the propeller shaft and the crank shaft.