Prop number decode

C

Coach

Seaman Apprentice
Joined
Jul 26, 2003
Messages
46
Searched the forums, but don't find my answer.<br />Trying to find the diameter and pitch of the two props I have. Both need to be reworked, but wanted to price new ones first. Thought I would find the diameter and pitch on the hub, but only find this number; 48 77350 A40 23P<br />Both props have the same number. They are used on my 1995 Force 120, pushing an 18' Astro, Fish/Ski. Thanks
 
S

Spidybot

Lieutenant Commander
Joined
Apr 4, 2002
Messages
1,734
Re: Prop number decode

It's a 12 1/2" dia, 23" pitch aluminum Quicksilver prop.<br /><br />Compatible with Mercury motor range 75-115 hp (4-cyl) which gives you plenty to choose from.<br /><br />Check offers on this site and on the net.<br /><br />Max rpm at wot is 5000-5500, gear reduction is 1.93:1 - for your motor.<br /><br />The closest Force prop was sold under part# P721-1 (13" x 23").
 
C

Coach

Seaman Apprentice
Joined
Jul 26, 2003
Messages
46
Re: Prop number decode

Wow...what a quick response. Think I'll go for the new ones. Thanks a lot fellas. ;)
 
C

Coach

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Joined
Jul 26, 2003
Messages
46
Re: Prop number decode

Just thought of a few more ???<br />I'm maxing out at about 4800 RPMs. But, I like the low end revs to pull the boys up on wake boards. Would you recommend keeping same diameter and pitch, or something else? Seems like I'm losing a little RPM on the top end with this prop.<br />Thanks
 
S

Spidybot

Lieutenant Commander
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Apr 4, 2002
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1,734
Re: Prop number decode

You should stay within recommended wot range. I'd definately go two inches down. Gives you significantly better hole shot and the 'nice and soft pull' can be managed by adding throttle the same way: Nice and soft.<br /><br />Better control at idle and more punch when you're entertaining an extra guest or two.<br /><br />And allows your motor to run as it was designed for, last longer and run better.
 
C

Coach

Seaman Apprentice
Joined
Jul 26, 2003
Messages
46
Re: Prop number decode

Thanks UU,<br /><br />I am new to this, so bare with me a second more...<br /><br />You suggest going down 2 inches! Not sure what that means? are you saying go to an 11" prop from what you said was the closest offer to my original? Or, are you saying go to a 10.5 inch from what I currently have (12.5" X 23 pitch)?<br /><br />Thanks for the advise and patience!<br />Coach
 
roscoe

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,683
Re: Prop number decode

What UU was saying, is to lower the pitch by 2 inches. Go from 23"pitch, to a 21" pitch.<br />If the diameter is the same, and the pitch is lewered 2 inches, your wide open throttle rpm will be increased by approx 400 rpm.<br /><br />This would put your rpm at 5200, smack dab in the middle of the recommended range.<br />Lowering the pitch increases rpm and gives a better holeshot/pulling power.<br /><br />Go here to learn about props. Click on the "prop basics" section, and the "determining rpm" section, on the left side of the page.<br /><br /> http://www.boat-props.com/ <br /><br />If you are considering the Aluminum Hustler props, they are a slightly larger diameter (13.25"). So you might want to get a 21" pitch, and a 19" pitch. The 19" will give you even better holeshot, but may put your rpms a little too high. Use the one that gets you in the 5000-5500rpm, and keep the other as the spare.
 
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