Numbers on my prop

[BlackBeastEnt]

ive got this number on my prop 832832a45p21
is this a 14.5 21 pitch?

i have a 2007 19’ Bayliner 195 BR with a 4.3 Mercruiser. I don’t know what drive it is or gear ratio.

Does this sound like the correct prop for this boat?

 

[ThomW]

We need a bit more information to really answer your question.
First, that is a 14.25 X 21 pitch prop.

To tell if its right for your boat, we'd need to know what your 4.3's max rpm recommendation is, and what you are getting for max rpm's out of that prop at wide open throttle.

If your max rpm's are below the motor's specs, drop the pitch a bit. If your max rpm's are above the motor's specs, raise the pitch a bit. Hope this helps some!

 

[BlackBeastEnt]

Thank you. Is there some kind of prop decipher code you use? I’ll have to get the rpm info.

 

[briangcc]

IF you do a google search on your prop number it comes up with the info on pitch and diameter. Generally speaking, the number after the P indicates the Pitch.

Whether the prop is right for the boat or not you need to determine the info in the sticky - WOT and your RPM range. Once you have that you can determine if the prop is correctly pitched or if it needs to go up/down to get you into the proper operating range.

To give you an example....my Chap in my signature has the 4.3 MPI 180HP variant of your engine and with an Alpha One Gen II 1.62 ratio drive I swing a 4 blade 19P prop as setup by the selling marina. I would wager this is close to correct but I can't confirm as I'm still in my break in period on the motor - no high RPMS yet.

**Your drive ratio is on the side of the drive, probably next to the serial number.

 

[BlackBeastEnt]

So I was out today and the rpms for my boat is somewhere between 4400-4800. I had it WOT and was getting about 4300 rpm and going 37 as per gps. And that was with the wind! And I was the only one in the boat. I don’t carry around a lot of gear.

 

[BlackBeastEnt]

And how do I know if I need a LH or RH?

 

[WesNewell]

If you google the number it will tell you. RH is standard. or you could just look at the prop.If blades are like this (/) it's right hand. Like this (\) it's left hand. Unless you have a weird setup, all single out drives are normally RH iirc. You only need a LH prop for dual engine setups.

 

[briangcc]

I ran your numbers through the Mercury prop selector, I guessed you were at a 1.81 ratio for the Alpha, and it came back with suggestions in the 20 and 19 pitch range which to me seems right as you want to get your RPM's up a bit. If you have more specifics you can put the info in and figure out which direction you want to go:


https://www.mercurymarine.com/en/us/propellers/selector/#!/step-one


You might want to check some local prop shops to see if they'll loan you some props to test with so you can make a decision based on real world performance/testing.

 

[BlackBeastEnt]

Thanks all I appreciate it.