Sea Ray 280 Mercruiser 4.3 Alpha 1 prop?

[impy03]

Hello all,

I still have the stock 3 blade aluminum props on my Sea Ray, and I am looking to upgrade to a 4 blade prop for better holeshot and mid-range cruising power as I usually have a good amount of weight and people on my boat at any given time. So, my question is would a 14.125" 19" Pitch 4 Blade RH prop be a decent prop to purchase or should I go down to an 18 or 17 pitch?

Thanks in advance!

 

[Lazy Daze]

Hello all,

I still have the stock 3 blade aluminum props on my Sea Ray, and I am looking to upgrade to a 4 blade prop for better holeshot and mid-range cruising power as I usually have a good amount of weight and people on my boat at any given time. So, my question is would 4 Prop 14.125" 19" Pitch 4 Blade RH prop be a decent prop to purchase or should I go down to an 18 or 17 pitch?

Thanks in advance!

The more important thing to know is what you currently have and are you able to get the proper Max RPM out of the engines when running WOT... somewhere in the mid to upper 4K range. If so, the general rule of thumb is to drop 1" or 2" of pitch compared to what you have. If you're typically running with a heavier load, I would consider dropping another inch and just realize that when you are running light and WOT that you could over-rev the engines - but you can avoid that via the use of the throttles.

Do you have trim tabs and use them?

 

[impy03]

The more important thing to know is what you currently have and are you able to get the proper Max RPM out of the engines when running WOT... somewhere in the mid to upper 4K range. If so, the general rule of thumb is to drop 1" or 2" of pitch compared to what you have. If you're typically running with a heavier load, I would consider dropping another inch and just realize that when you are running light and WOT that you could over-rev the engines - but you can avoid that via the use of the throttles.

Do you have trim tabs and use them?

WOT RPMs is another issue I am currently working on. I am only reaching about 3500-3700 RPMs at WOT on both engines, but I am thinking once I change out my plugs to OEM spec as recommended, I should hopefully be back in the 4400-4800 RPM range. Regardless, both my current aluminum props are old as dirt and will need to be replaced at some point due to general wear and tear.

Yes, I have trim tabs and use them as necessary depending on load and water conditions. They work well, but getting on plane and staying on plane is difficult with a heavy load using the current 3 blade prop setup.

 

[Espos4]

WOT RPMs is another issue I am currently working on. I am only reaching about 3500-3700 RPMs at WOT on both engines, but I am thinking once I change out my plugs to OEM spec as recommended, I should hopefully be back in the 4400-4800 RPM range. Regardless, both my current aluminum props are old as dirt and will need to be replaced at some point due to general wear and tear.

Yes, I have trim tabs and use them as necessary depending on load and water conditions. They work well, but getting on plane and staying on plane is difficult with a heavy load using the current 3 blade prop setup.

Whatever is causing your low WOT RPM could be affecting your low end power/torque and giving you issues getting up on plane.

Get the motors running properly first before you start messing with prop changes.

 

[Lazy Daze]

Tabs... just in case you aren't... KEEP using them, as much as needed, to stay on plane at medium speeds. They're a good tool.

Yes, get that RPM drop figured out before you do anything. Could be anything from needing new caps/rotors/plugs/wires... all the way to low compression. Can't do anything with props till the engines are running healthy.

 

[impy03]

Yes, get that RPM drop figured out before you do anything. Could be anything from needing new caps/rotors/plugs/wires... all the way to low compression. Can't do anything with props till the engines are running healthy.

10-4 will do! Thanks, fellas!