Evinrude 90 Hp v4 prop vs rpm

StingRay_90V4

Petty Officer 2nd Class
Joined
Aug 26, 2014
Messages
155
So I recently had our boat fixed. And it is stronger then ever due to the timer base being sticky for several years. My question in regards to my current prop is weather or not a new prop of the same size is in order. Or a decent ss. The current 20 year old aluminum omc 13 1/4 x 17p is a little banged up here and there. Nothing to overly serious. But a few small pieces here and there missing . As well as some mild wear. The engine will turn the prop to 5600-5700 rpm at 44 to 45 mph. I have read some on here say 5500 rpm and some say 5800 rpm for the v4 crossflow. I am near the upper end of the two numbers. I am NOT looking for anymore extra speed. The boat is fast enough as is. My question remains as to weather or not my rpm at wot is good. I assume so . And if I was to purchase a new prop. Should it be ss or aluminum ? And what differences would I see in the two ? Thanks all .
 
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b.gagnon

Master Chief Petty Officer
Joined
Apr 28, 2001
Messages
835
I would get A 17p Stainless... you will loose 100-200 RPM depending on the cup. You are running at the upper range so loosing a few rpm wont hurt you!
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
What kind of lake/river are you using it on, shallow, deep, rocky bottom, sand bottom, loon crap bottom? If you never see shallow or rocky bottoms, then a Stainless might be for you, if you boat in hazard filled water, then maybe you should stick with stainless. I say that as while AL props bend/break easily on impacts, SS tends to keep hammering into a rotating mass of metal, often resulting in a bent propshaft
Don't rev that engine too far past 5500, as it will be making less than its 90hp above 5000 rpm
 

StingRay_90V4

Petty Officer 2nd Class
Joined
Aug 26, 2014
Messages
155
The bottom of our lake isnt really rocky at all. Its pretty much all mud. With a few small rocks here and there. The lake is fairly large. Wide open. With absolutely no shallow points or islands or anything to hit or worry about. The only time I think our prop has ever hit anything was pnve or twice before when we had really consumers with no real rain at all and the lake level was down a fair amount. My father didnt have the engine up enough coming in to the dock. The engine hit bottom and that is were the few small dings dents and small pieces of the prop went missing. Normally when the lake is 3 to 4 feet higher . it is never an issue. There is a Doral 17ft boat across the lake from us that has a Johnson 90 v4 on it. He is running some kind of ss 4 bladed prop. And the bow lift it has is insane. At full speed wot there isnt much if his hull in the water. He says his boat does 46 to 47 mph. Idk if he is just making it up or not. I could almost see it. Now that our 90 on a slightly smaller boat will do 44 to 45. Is a 4 bladed prop worth looking in to ?
 
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