looking for correct prop

reinsboot

Recruit
Joined
Oct 13, 2007
Messages
1
I have an 87 thundercraft 18ft runabout 175hp. I was wondering if anyone could tell me the factory diameter, pitch and details on my prop. I have no owners manual so i was hoping someone could help me out.

Thanks Dan
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,082
Re: looking for correct prop


Ayuh,........ 175hp What,..??..??.......

There isn't necessarily a Factory Prop.........

You tell Us, What the Driveline is,.....
What the WOT RPMs are,+ possibly the WOT Speed.......
Then We'll try to help you dial it in to what Works the Best for your application.........
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: looking for correct prop

As in the previous post, you must understand that props are the "transmission" for your boat. There is no "standard" prop for yours or anyone elses boat and even if you had an owners manual, it would not tell you what the proper prop is because they don't know how you operate your boat. The prop you need depends on the load you typically carry, the amount of power you have available, and hull design. Although you told us what you have in that regard, you have not provided any of the details we need to help you. It really helps to know if you have an outboard or an I/O and who the manufacturer is. Then its nice to know what prop diameter and pitch you have now, what the wide open throttle rpm is with a normal load, and what maximum speed is. "About xx" is not a good response. If you have an I/O, the gear ration of that unit is needed as well. If you are coming to the conclusion that prop selection is not an "exact science" you'd be right. Without a base line to start from -- that process is merely a crap shoot.
 
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