New at this

Skinny

Cadet
Joined
Nov 28, 2007
Messages
18
I have a 18" Starcraft 1810ss with a 4.3 mercruiser. I have a 14" prop with a pitch of 21. What is this good for?
 

HyperFox

Petty Officer 3rd Class
Joined
Dec 31, 2007
Messages
78
Re: New at this

Fishing.

lol.. Couldnt tell ya and I couldnt resist. The prop experts will be here any time now..
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: New at this

Unless someone has an exact same boat, we don't have a clue what it's good for. The prop is the transmission for the boat. It needs to get the boat out of the hole and at wide open throttle it needs to allow the engine to run in its recommended RPM range which is probably in the 4600 - 4800 RPM range. If the engine can't reach that rpm the prop has too much pitch. If it revs higher than recommended it has too little pitch. Of course all of that depends on whether the engine is developing full power (as in proper tune up and not worn out). Make some wide open throttle runs with an average load and note the RPM. Then post the results.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: New at this

I have a 18" Starcraft 1810ss with a 4.3 mercruiser. I have a 14" prop with a pitch of 21. What is this good for?

What style of propeller, 3 blade, 4 blade, 5 blade, high rake??? And what material is it made out of? Is it a Mercury prop or an aftermarket? Most importantly, does the engine reach the maximum recommended WOT RPM range for that engine (4400-4800)? And are you happy with the performance of the existing setup?

Chris........
 

Lakester

Chief Petty Officer
Joined
Nov 17, 2007
Messages
428
Re: New at this

I have a 18" Starcraft 1810ss with a 4.3 mercruiser. I have a 14" prop with a pitch of 21. What is this good for?

hello,

assume u mean this is the prop u r currently using? :confused:

a) if i bat ur specs against mine... 14 1/4", 17 degree pitch, 3-blade alum... i would say ur prop suggests that while u weigh a bit more than me, and i am assuming u r a v6? it tells me that u have more power, hp and torque than i, so u can handle a 21 degree pitch prop and not bog engine from proper rpm range at WOT. usually 5-5500 rpms or so.

b) so if u have less pitch on boat now this may give you more mph at mid throttle, but not WOT rpm. sorta like tall gears in a car.

c) i doubt u r running currently more than 21 degrees of pitch.

regards

lakester :cool:
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
Re: New at this

Skinny, I used to run a 21" pitch Stainless Rapture on my 1988 19" SeaRay Sorrento Bowrider 4.3LX/Alpha I. I would get 4500RPM at WOT, and about 40-42MPH. A 19" pitch prop gave better holeshot, and since I did not ever run the motor at WOT for any length of time, I never overreved it. I stuck wit the 21" pitch prop to save a bit of gasoline.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: New at this

4.3 is a v6
i dont know if 5500 is a good rpm....

mine i wont go above 4800 for fear of things flying.

what your looking for is a prop that will give you best performance for what u need (pulling or racing).

every 1" prop pitch increase will lower your rpms approx 200 rpm.

it just depends on what you want to do to find the best prop for you.

can some one find a previous link that runs thru the basics for him? i still cant figger out how to post a link....some times it works.....sometimes it doesnt

cheers
oops
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: New at this

oh btw...

welcome to i boats!
good people here with lots of know how......

try the search feature...

oops
 
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