I'd like to see if anyone has any info on the pros and cons of the three blades vs. the four blade options.

My setup is this: '92 Baja 240 Islander with a 502 mag, Bravo 1 drive and a 21" Mirage. Boats runs 72 (speedo) at 5200 rpm (short runs). I would like to lower the rpm's but not sacrifice on top end (or obviously increase top end). I've considered going with a Mirage 23", but I'm currently not satisfied with the excessive amount of throttle it takes to get out of the hole or merely keep on plane. I believe that the 23" would worsen the holeshot but would take care of lowering the rpm's without too much speed loss.

It seems like the logical choice would be a 4 blade. But which size? What's the pros and cons of the Bravo's and the Rev 4's. Will I have to give up top speed?

Last question, I swear... What's the benefits or drawbacks of a cleaver vs. a Mirage? How does the cleaver affect rpm's and top speed?

Open for suggestions. Thanks for the input, this board is GREAT!

Propeller selection is pretty easy once you have some info to start with, which you do. It's pretty simple you just have to use is some math. Take 5200 rpm x 21 P = 109,200 inches per 5200 revolutions. Now if you put on a 23 pitch Mirage your RPM will drop to 4900. Take 4900 rpm x 23 P = 112,700 Do you see? The 23 P prop will make your boat a bit faster. Now to gain approx 3 MPH lab finish the 23 P Mirage. Now you will gain even more!
Your boat will gain out of the hole performance and mid range but loose in top end using a Bravo I 4 blade. But Mercuriser dose not offer a Bravo I in your pitch range.
The 4 blade to run would be the Revolution 4 blade. Cleaver is old technology GARBAGE
don't go backwards.

'Fella

I agree with the 23" Mirage to lower the rpm's. I think that 5200 is too much for the 502. From what I read, lab finishing will bring the rpm's back 200-300. This hull is light and the engine is heavy. I need some stern lift to help get some out of the hole performance. Even with full tabs the bow raises high and does not want to stay on plane at slow cruising speed. Does lab finishing help in this regard?

Thanks.

Everyone is under the assumption that when you lab finish a propeller it will automaticly raise the RPM of the engine. That is not the case. The propeller is lab finished to make it perfect for the boat it is running on. What you are trying to accomplish is turning the biggest pitch propeller at the most rpm the engine was manufactured to run at.

KC: Welcome to the board.

If you do a search on your topic, you will find many similar questions, and 10X more answers, but keep in mind prop selection is some where between black magic and science. Some props provide bow lift, and some stern lift, but generally at speed. May not be a factor in hole shots. One of the best suggestions in prior postings is to work with a good prop shop that will let you try different ones on your boat. Good Luck.