what pitch

[backyardracer]

I have a 1977 tri hull 16ft with a 120hp mercuser pre alpha the rpm range on the motor is 3900 4300 dont really know what it weights the prop that i got with the boat is reving 5000 and i can not figure out what pitch it is

 

[hwsiii]

Re: what pitch

Racer, we welcome you to the forum and hope to be able to help you with the questions you need answers to. If you will supply us with the answers to the questions listed below we will have everything we need to help you with your quest, in most cases.

Boat and Motor

H

 

[backyardracer]

Re: what pitch

I think it way about 2200lb no extras on this boat really i think gears are 1.98:1
153 cid, 120 4cyl, 2200 2400lb

 

[steelespike]

Re: what pitch

Prop number usually appears on the barrel or under the prop nut.
No numbers? a prop shop can tell you the size.
Without prop size and present max rpm and speed its very difficult
to figure. A tinytach is reasonable,easy to install) and a gps are excellent for speed and rpm.If you read the stickies at the top of the page and the helps on the iboats prop page you'll better understand prop science.

 

[backyardracer]

Re: what pitch

Ok its a 15inX17p 3 blade alumminum reving 4800rpm maybe alittle more if i would have let it the max on the motor says 3900 to 4300 it ran about 35mph by the speedo and i know they are not very acurate. The old prop was alittle beat up to i just got this boat i'm more of a car man getting in to a boat world just a little bit diffrent
I think i would like to go to a 4 blade but dont know i'm more of a fishing kinda person thanks for the info so far like i said this is alittle bit out of my car world