how to find prop pitch?

rastoga

Cadet
Joined
Oct 15, 2001
Messages
23
I recently put a used yamaha 40 on my boat. I'm just barely in the RPM operating range with a normal load. I'm at 4600 and the operating range is 4500-5500. I'd like to drop the pitch a bit, but I need to know what pitch the current prop is. Are the prop dimensions written on the prop somewhere? It is a stock yamaha aluminum prop.
 

Fouled Plug

Ensign
Joined
Jun 29, 2001
Messages
935
Re: how to find prop pitch?

I think you'll find it stamped lengthwise on the hub of the prop. Every drop in pitch theoretically will bump your RPM's up about 200 or so. There are other variables like cupping, diameter, etc. Let us know what you find on your current prop.
 

rastoga

Cadet
Joined
Oct 15, 2001
Messages
23
Re: how to find prop pitch?

On the hub there are 3 numbers, they say y-3, G, and 13. <br /><br />If 13 is indeed the pitch, then the diameter should be 10 3/8. That's the only diameter prop yamaha currently makes with a 13 pitch and aluminum construction. At least that's what they list on their website for use on 40 hp motors.
 

rastoga

Cadet
Joined
Oct 15, 2001
Messages
23
Re: how to find prop pitch?

So if it is a 10 3/8 x 13, should I go with a 10 5/8 x 12, or a 11 5/8 x 11?
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: how to find prop pitch?

If you can borrow a 12, Rastoga, try it out. Another option is to buy a 12 with trade option if it doesn't get you up to about 5,000 with average load. <br /><br />Otherwise I would go with an 11.<br /><br />Red sky at night. . . <br />JB :)
 

araiha

Petty Officer 2nd Class
Joined
Sep 8, 2001
Messages
121
Re: how to find prop pitch?

Rastoga,<br /><br />If you can find the yamaha part number, something like 6H5-45945-00-EL, I have a rigging specs manual and can tell you what the pitch is. Normally the number is on the outboard end of the hub just outside the rubber coupler on the prop's frame. Just post the number on this site or email me at araiha@hotmail.com
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: how to find prop pitch?

If you dont want to buy a new prop. A prop shop can re-pitch your prop. But I think everyone should have a spare..But heck what do I know..
 

Rex

Chief Petty Officer
Joined
Aug 12, 2001
Messages
424
Re: how to find prop pitch?

THEY CAN ONLY CHANGE THE PITCH BY 2 DEGREE.<br />REX A.
 

Rex

Chief Petty Officer
Joined
Aug 12, 2001
Messages
424
Re: how to find prop pitch?

WHERE CAN I FIND A TABLE TO TELL ME THE <br />YEAR OF THE ENGINE BY RHE SERIAL NUMBER?<br />REX A.
 

araiha

Petty Officer 2nd Class
Joined
Sep 8, 2001
Messages
121
Re: how to find prop pitch?

I have a yamaha factory rigging specs manual that lists all the part numbers for all their props and the associated pitches. Picked it up on ebay for $25 and worth every penny.
 

araiha

Petty Officer 2nd Class
Joined
Sep 8, 2001
Messages
121
Re: how to find prop pitch?

Your other choice is to go to a yamaha dealer and see if you can talk them out of one of their outboard accessories catalogs. It lists them by part/size/pitch as well. This option is free.
 
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