You are absolutely correct Powderpro. 2900 is max. I guess I was thinking of my previous Yanmar 4 cylinder screamers. I am not married to 2:1 and can adjust the ratio I am searching for or eventually will buy. 2:1 was simply an offering. I understand trying to slow the shaft down but is there an ideal shaft RPM or ratio of shaft/flywheel RPM to shoot for? Is slowing the shaft strictly to ad longevity to rotating parts or is there point where the greater speed of the shaft reduces prop performance?