Would like to move to a 4 blade prop

[jsmaeb1215]

Hey all. Looking to move from a 3 blade prop to a 4 blade prop on my 2015 Bayliner 195 Deckboat with the 4.3l MPI. Just looking for some advice on my options. I currently plane out at about 20 mph, and run roughly 46mph at 4800rpm's. We rarely go over 40 mph and when we do will hit 40 for 10-15 seconds and thats about it. We are really looking for a better holshot/midrange power. Im not sure if the 18 pitch is going to provide that extra power we are really looking for. I appreciate the input!

Stock Prop
14.5x19 3 Blade

Prop Options
14.5x18 4 blade
14.5x17 4 blade

Im also open to other prop suggestions!

 

[alldodge]

Looks like your in the correct range for the prop already. A 4 blade prop takes more HP to turn it but bite more. If you must go to a 4 blade I would suggest the 17 pitch. To get better hole shot you could go to a 3 blade 17 and have it cupped. The cupping will increase bite but also will cause you to over rev at WOT

 

[jsmaeb1215]

Looks like your in the correct range for the prop already. A 4 blade prop takes more HP to turn it but bite more. If you must go to a 4 blade I would suggest the 17 pitch. To get better hole shot you could go to a 3 blade 17 and have it cupped. The cupping will increase bite but also will cause you to over rev at WOT

I was also leaning towards the 17 pitch and just accepting the fact that I will have to watch my RPM gauge when going WOT.

I will say this. With the current prop and the boat basically fully loaded (1250lbs max:1475) getting on plane can be a bit rough. I basically have to got WOT to get it out of the water with that load. Now when its just my wife/myself/2 kids (700lbs) it jumps up on plane real fast.

 

[alldodge]

The rule of thumb is you go down 2 inches of pitch going from 3 to 4 blade. This keeps you in the same WOT rpm range, The 3 blade 17 or 18 will over rev. I would prop the boat for the way you use it most the time, not the every once in a while.

I use to pull several skiers at one time, so when I was going to do it, I would swap props (from 21 to 19), have some fun, then swap back when finished

 

[jsmaeb1215]

The rule of thumb is you go down 2 inches of pitch going from 3 to 4 blade. This keeps you in the same WOT rpm range, The 3 blade 17 or 18 will over rev. I would prop the boat for the way you use it most the time, not the every once in a while.

I use to pull several skiers at one time, so when I was going to do it, I would swap props (from 21 to 19), have some fun, then swap back when finished

Then I think the 14.5x17 4 blade will be my best bet. Does anyone disagree?

 

[jimmbo]

The cupping will increase bite but also will cause you to over rev at WOT

Cupping, added to the trailing edge effectively adds pitch, which lowers rpm

 

[Maclin]

The 4.3MPI will watch your rpms for you, just sayin'

 

[alldodge]

Cupping, added to the trailing edge effectively adds pitch, which lowers rpm

Agree, figured with a 17 it would be closer to a 18 not full 18 just closer. Figuring an 18 would be hard to find