Prop 1975 Evinrude 115

rnx22

Recruit
Joined
Apr 27, 2014
Messages
3
What's the best prop for a 1975 Evinrude 115? I use the boat for fishing & tubing.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,032
????-------Not much to go by at all.-----------What size boat and what is the weight when you are using it ?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
We are really not trying to give you a hard time.We just want to be sure you get what you need.
Your probably trying not to be long winded but we need information.
You should read the stickys at the top of the prop forum.
We need your present prop size,near the base of the blades or under the prop nut.
A lightly loaded wot,(wide open throttle) test run. get us the prop size rpm and gps speed.
This will tell us how well your setup is working.
Your boat dry weight is 800lbs but we need your typical total weight in round figures.
You need an accurate tach to tell the results of your prop selection.The test run will help
tell if the tach is accurate. I can tell you that a healthy 115 on a boat like yours would "probably" use a 17" or 19" pitch.
 

Roj115

Petty Officer 2nd Class
Joined
Aug 21, 2004
Messages
102
I have a '74 Johnson 115 on a 16' '74 Starcraft American bowrider, It is a fibreglass runabout v hull boat. Not too heavy. Is yours Aluminum or Fibreglass?

My boat came stock with a 19 pitch aluminum but it was too big for the motor on that boat. We put a 17" Al on it and that gave us the desired 5500 rpm at WOT. We replaced that with a 15 pitch SST and that also gave us 5500 rpm at WOT. The boat is great for waterskiing and tubing. Great hole shot. Goes about 35 at full speed which is faster than what I water ski at which is 32 mph.

You want your engine to hit a max of 5500 rpm at full speed. If your current Al prop gives you 5500 at WOT, then you should probably drop the pitch by 2" to go to a stainless steel. Like I said, a 15" SST works great on my boat with the same engine. Don't know how similar your boat is to mine...
 
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