Hello from George and his new/old Brewer 12.8. I have obtained a maxprop 3 blade classic 17 inch dia . Its in good shape and thinking of installing it. Boat has a Yanmar 75Hp 4JH3 -TE diesel with a 2.17:1 ratio. Current prop is 17dia-- pitch not known. Previous owner was cruising at 2600-2800 which gave speeds of 6 to 6.7kn. Yanmar book says max RPM s for this engine is 3800. 75% of that is 2850 85% is 3230. I kind of feel its now over-propped. Is it? What should pitch be set on the Maxprop? Thanks all.