Changing props. What one to get?

[wyelkhunter73]

I have a 2003 procraft 180 combo(it is a heavy boat) and a mercury 200 efi. Manual jack plate with 5.5" of set-back. Currently running a SS laser 2 21 pitch. WOT is only 5000 rpm gps speeed 42 to 43 mph, with fishing gear and 2 people. Elevation here is 5400 ft. I have played with the motor height and have it in the optimal position for the current set up. Is there a better prop option? Or should I just go with a smaller pitch laser 2 prop?

 

[jimmbo]

What is your Engine's WOT Rpm Range?
How Heavy, as in, is it Full of Water?
Even Allowing for the Altitude, your speed seems Low

 

[wyelkhunter73]

What is your Engine's WOT Rpm Range?
How Heavy, as in, is it Full of Water?
Even Allowing for the Altitude, your speed seems Low

WOT range 5000 to 5800. Probably aeound 3000lbs loaded. 2 people half tank gas and all the fishing gear.

 

[jimmbo]

"Probably" really is nothing, just an Assumption. Have you ever Weighed it at a Scale? Take it, put it on the Scale, unhooked from tow Vehicle. You will need to subtract the Weight of the Trailer, Manufacturer should be able to provide that info, or when the Boat is in the Water, weigh the Trailer

 

[wyelkhunter73]

"Probably" really is nothing, just an Assumption. Have you ever Weighed it at a Scale? Take it, put it on the Scale, unhooked from tow Vehicle. You will need to subtract the Weight of the Trailer, Manufacturer should be able to provide that info, or when the Boat is in the Water, weigh the Trailer

thanks. no scales around me so I was just adding up the boat dry weight and all my gear and motor etc...

 

[jlh3rd]

assuming nothing is wrong...including a waterlogged boat, as implied.
You didn't say what you are trying to do.
props aren't miracle workers. You can fine tune, but usually trade speed for torque.
Your 800 rpms from max WOT. So you can drop 1 inch in pitch and get the rpm's to 5300+/- ? , at that load. If that's what your shooting for. But you may lose speed. Drop 2 inches and you'll be closer to 5800 but with just you on board, you'll exceed WOT rpm's if not throttled back.
I propped my pontoon to pull teens on tubes, so that kept me at 56-5700 rpms. I didn't like being at 5300 or less especially when turning with the other prop. My top speed, by myself, dropped, but I was close to the rev limit.

 

[wyelkhunter73]

assuming nothing is wrong...including a waterlogged boat, as implied.
You didn't say what you are trying to do.
props aren't miracle workers. You can fine tune, but usually trade speed for torque.
Your 800 rpms from max WOT. So you can drop 1 inch in pitch and get the rpm's to 5300+/- ? , at that load. If that's what your shooting for. But you may lose speed. Drop 2 inches and you'll be closer to 5800 but with just you on board, you'll exceed WOT rpm's if not throttled back.
I propped my pontoon to pull teens on tubes, so that kept me at 56-5700 rpms. I didn't like being at 5300 or less especially when turning with the other prop. My top speed, by myself, dropped, but I was close to the rev limit.

I am just wanting to get my rpm up to On acceptable number preferably on the upper end of the range. I am going to do this with a smaller pitch prop. I know I will lose speed but I am more concerned about being in the correct rpm range than how fast my boat goes. My main question is there a better prop to try than a smaller pitch laser 2. I have been told in the past that the laser 2 isn't the optimal for my boat.

 

[jimmbo]

I doubt you will lose much, if any Speed. Though the Pitch is less the Rpms go up, and since you are at the Bottom of the Rpm Range, the Motor will be making more HP as Revs increase.
In the 50 yrs I have been swapping Props, I found that within a Given Prop Line, there isn't too much Difference in Top Speed, as long as you are within the WOT Rpm Range, If you are below the bottom End, because of Serious Over Propping, dropping down in Pitch can result in an Increase in Top Speed

 

[jlh3rd]

I doubt you will lose much, if any Speed. Though the Pitch is less the Rpms go up, and since you are at the Bottom of the Rpm Range, the Motor will be making more HP as Revs increase.
In the 50 yrs I have been swapping Props, I found that within a Given Prop Line, there isn't too much Difference in Top Speed, as long as you are within the WOT Rpm Range, If you are below the bottom End, because of Serious Over Propping, dropping down in Pitch can result in an Increase in Top Speed

that has not been my experience. Same boat, load, conditions. Regardless, speed was 3 mph lowest to highest.