---

The boat is a1980 Outrage 21, the engine is a 2003 115 Ficht Ram Evinrude.
I do not have the spec of the prop on the boat but it's a 17". I will have a closer look later but what would work best for this combo?
I ain't no fisherman and do not plan to troll at all, and I will use the boat for 15 miles trips to the islands around, tubing with the kids and allthe fun stuff we could think of.
The sea is often mildly choppy around here.

---

The 2003 Evinrude 115 has a 2:1 gear ratio (assuming you have the 20" shaft length) and a 5250-5750 recommended WOT RPM range.

If the boat has a top speed of about 38 MPH, then you should be using a 15 inch-ish prop, though that depends on exactly what model of propeller is being considered.

How fast does the boat go now with the 17" pitch propeller?

At what is your maximum RPM now?

---

The boat is still in restoration, and I haven't tried the engine on it yet. I am just sort of planning what I should look for if I am deceived by the first run.
The engine was used on a 17' river boat to survey other ski boats and had very low ski time itself.

---

Can you confirm the motor is a 20" shaft length (Long) and not a 25" shaft length (Extra Long) model?

Don't bother with the propeller you have now. Sell it and save up for a good stainless steel propeller.

---

Yes it's a long one, 20".

---

I'm not sure what availability you have in France, but if you want to buy used look for an old OMC SST II in the 13-1/2" x 15" size. That was a common and quite good propeller.

If you want new, I can ship you any Stiletto or Turbo propeller you want for the added cost of postage to France.

---

Thanks it's nice of you ;-) I will look for one like you're talking about.

I went to my shed and the prop is a 13.25x17 aluminium. No name on it, must be a BRP?

---

There is a part number cast into the end of the hubb. That will tell you exactly what it is. It might be a BRP or an older OMC or some aftermarket brand like Michigan.

It does not really matter. It is to much pitch for your application and,if in perfect condition, be worth about $50 in the USA.

---

Ok still no perfect trial day up to now, very choppy and windy. So with the Ficht-Ram 115 (brp) and with the same prop as stated above (17) 2 adults ads 20 gal of fuel I went up to a steady 33.4 knots @ 5000 rpm.[38 mph] No way I could rev higher. I will try to find a 15 prop for a run and see...

The engine is on the second hole from the top and I find it a bit low. Should it be on the third one?

I have read that the 21 Banana doesn't respond well to trimming, I think in my case anyway, it's false. Maybe due to the engine being a bit low... ?????

Your advice, Thanks, Fred

---

Fred -

From the last photo on your personal page, I see the motor is mounted "1-hole up".

What will be the typical load for the boat? You want to prop the boat for the typical load.

I would raise the motor 1 hole and retest. You may even be able to go up to 3 holes up. It's all about testing.

Raising it a set of holes will raise WOT rpm's 150-200.

I second Tom's advice for changing to the stainless steel prop.

---

4 euro adults and gear... (+/- 680 pds) + 25 gal of fuel

---

Good day yesterday... Mirror like water, no wind.
2 aduldts - 37% fuel - no gear - Trim 50% - +/- 5250 rpm = 39.2 mph

That is with the engine in the first hole up and the 17" prop... What do you think will happen with the 15" SS prop and 2 holes up?

---

I would take the incremental approach.

Test the motor height change first with the same prop. Remember the load/fuel needs to be considered.

Is the 15" pitch prop from the same manufacturer and model of the 17? If it is, you should try it and test the results AFTER raising the motor.

---

Funny comment about the "euro" adults @ 150lbs/each! I guess 4 north americans adults with gear would be closer to 1000lbs...;-)

---

y
It does matter for this test and it's not relevant for anything else ;-)

---

I will do just that, thanks, Fred

---

On a side note: Fred, being in Normandy, is there a lot of ceremonies/commemorations today in the area for the D-Day 70th anniversary?

---

Funny... Caen is in fact my last name! But part of my family is indeed from Normandy.

Yes, it's really big this year...

---

I had the engine raised 2 holes and an SSP 15 prop fitted. Rough water prevented me with WOT testing but a 30 miles + trip was enough to see the change. This isn't the same boat. At 4000 rpm and 20knots I was burning 5.2 us Gal/h before, now its down to 3800 and 4.1us Gal/h for same speed, wind and water. She is less responsive to trim now but the ride is better. I can't wait to,try her at WOT.