suggestions on propping a 19'6" 1982 with 4 blade

[trevor650]

I currently have a three blade prop alum 15x17  would like to go to a stainless 4 blade  it has a johnson 150 2-stroke on it now. Any suggestions would be apprecaited. seems like she likes to porpoisea little even on a smooth water motor trim all the way down she turn at 5400rom

[fitz73222]

Hey Trevor,

The standard rule is to drop 2" of pitch when going from 3 blades to 4 because of the increased surface area and bite you get from the extra blade. So you should be looking for a 15" 4blade to get started.

[Capt Matt]

If you get a vented 4 blade i would suggest a 17p
On my last boat I ran both a 21p 4 blade and 21p 3 blade both turning 5750 rpm trimmed up
Capt Matt

[Blue Agave]

I run a 19 pitch power tech 4 blade on my 19-6. I can get 6000 rpms trimmed out of my Mercury. Be sure and check out what the max rpms are for your motor, I believe that johnson and evinrude are only meant to turn 5400/5500 tops but I'm not positive.

[Aswaff400]

my OMC manual states anything within 5000 to 6000 rpm is good i currently run on the low end, right at 5000 with my 23p

im with matt, a vented 17p would be good start

which PT prop you running fernando?

[Blue Agave]

my OMC manual states anything within 5000 to 6000 rpm is good i currently run on the low end, right at 5000 with my 23p

im with matt, a vented 17p would be good start

which PT prop you running fernando?

Can't remember Aaron, I've been running it now for eleven years or so. All I know is it's a vented 19 pitch