# Microskiff 25hp prop advice (Update)



## MikeCockman (8 mo ago)

I have a 14’ MicroSkiff I built on a Randall Craft hull. 
The Boat is powered by an 2005 Merc 2s 25hp.Rated 6000rpm WOT.

It currently has a 3 blade OEM alum 10.38x13 turning 5800 rpm @ 29mph. 
But hole shot is lacking.
I got a hold of new 4 Blade 10x13 Alum prop for cheap and it’s returnable so why not. The hole shot is a 100 times better, but it only turns 5500rpm @27mph. 


So my question is,
If I were to drop to a 11p or 12p would top speed increase with the increased RPM?
Or In other words, does spinning a smaller prop faster = more top speed? 

The answer is yes. Or Atleast in my case it is. I Dropped to 10x12 from the 13, 4 blade aluminum and it’s fantastic. Wot Rpm’s are 5920 at 29mph with an amazing Hole shot as well.
Mission accomplished. 

Here are the numbers. 
3 Blade 10x13. 4 Blade 10x13. 4B 10x12
[email protected] 5500/27. 5920/29
[email protected] 5000/24. 5000/25
[email protected] 4500/21. 4500/21


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## Smackdaddy53 (Dec 31, 2012)

Increasing pitch will drop RPM. If you want better hole shot and reach a max of 6000RPM add cup for hole shot and drop pitch to offset drop in rpm due to added cup. 
Your best bet is call a prop shop instead of going back and forth. It’s a waste of time and money when you could just get with a prop shop and get the correct prop on first or second try.


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## MikeCockman (8 mo ago)

Smackdaddy53 said:


> Increasing pitch will drop RPM. If you want better hole shot and reach a max of 6000RPM drop pitch and add cup. Your best bet is call a prop shop instead of going back and forth. It’s a waste of time and money when you could just get with a prop shop and get the correct prop on first or second try.


Yeah I get that, but I got 50$ in a new 4 blade prop. Ain’t no prop shop gonna get in that ballpark with cost.
I also understand what pitch and cup does to RPM, Engine running height Ect.. But was curious if the added RPM that’s gained would offset the loss in pitch. Or would it still remain equal?


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## cody0707 (Feb 24, 2017)

What's the spline count on those Mike? I have a 3-blade 9.25 x 12.5P and a 9.3 x 11P 4-blade. They are both 10 tooth spline. I live in Tallahassee and could let you borrow them to see if they help.


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## devrep (Feb 22, 2009)

if you're getting 27-29 mph with a 25 on that relatively heavy hull you are doing pretty good.


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## MikeCockman (8 mo ago)

cody0707 said:


> What's the spline count on those Mike? I have a 3-blade 9.25 x 12.5P and a 9.3 x 11P 4-blade. They are both 10 tooth spline. I live in Tallahassee and could let you borrow them to see if they help.


They are 10 spline I think. But I believe the 05 down 2s are different than 06 newer, and the 4s. 
Both of the ones I have are 10” props as well. 
I really appreciate the offer though.


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## SS06 (Apr 6, 2021)

I think stick with what you have....ur gonna spend several hundred$$$ for 1-2mph.


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