Prop Sizes

MMHagler

Seaman
Joined
Apr 10, 2011
Messages
72
I have a 10x11p prop on my 1976/35 Johnson and a guy on the internet has a 9.5x11p prop plus a 9.75x9.5p and want $60 for both and they are brand new,never used because they didn't fit. Are they worth it,what do the numbers mean and most of all would they fit my boat?? Thx
 

ONERCBOATER

Chief Petty Officer
Joined
Oct 11, 2010
Messages
536
Re: Prop Sizes

This would be better placed in the Props section of the forum.

don't know if they will fit your engine or not, the big thing is the spline count for fitting and diameter of the shaft. 9.5 x 11 p is roughly equivalent to 10 x 11 p 9.75x 9.5 would be a lower pitch and would allow your engine to rev more.... could be good or bad depending on your current rpm and type of load the engine is subjected to..... diameter of the prop + or - 1" is for all practical purposes inconsequential as long as it doesn't strike your ventilation plate by being too large a prop.

the numbers and what they mean. in 10x11p the 10 means 10" diameter the x means "by" and the 11p means 11" of pitch (each time the prop turns one revolution the blades would move 11" fwd in the water.... well in a perfect world reality is a lil different but the 11p allows you to compare it to a 9p or 19p and have an idea of what your getting) more pitch should mean faster, less slower... in reality your aiming for a prop that allows your motor to come up to its power band... depending on engine 4500 to 6000 rpm so as not to over rev it nor lug it. think of the pitch as a gear in a cars transmission.... but you only get one so you chooose the one that suits the engine and boat best.

Sean
 

MMHagler

Seaman
Joined
Apr 10, 2011
Messages
72
Re: Prop Sizes

Thx very much,that answers everything I needed to know and more. Thx Sean
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Prop Sizes

It is very important for your motors health and performance to operates within it's wide open throttle rpm range,5,200 to 5,800.we can help you determine if your setup right.
 

MMHagler

Seaman
Joined
Apr 10, 2011
Messages
72
Re: Prop Sizes

I have had it wide open and it doesn't sound to be reving to high. I was going to buy the props because it sounded like a good deal and if they fit my motor that would be a bonus. There is no speedo or tach but I think I would know if something is up in the rpm area.
 
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