Prop size

[Bob Fischer]

What is the correct size prop for a 1985 C27 with a Universal M18 (14hp). It's a fin keel which weighs in at about 6800 lbs.

 

[Ron]

Can't give you a precise answer but can tell you the parameters that are important. Going back to basic mechanics, a prop (the "screw") is an inclined plane wrapped around the shaft

 

[Don]

My 86 c27 with M18...

came with a 13x10RH, two blade. I don't think it has ever been off, so I had it balanced and repitched to 13x12. I picked up about .4kt and still have more engine than prop. That means, I can go to red line in gear. I can get 5.6kts @ 2600rpm in flat water. Hope this helps.