1999 OUTRAGE 17 Yamaha 150-HP Re-Power

[biggerstaff]

I am re-powering my 1999 OUTRAGE 17 with a 2022 Yamaha F150XB engine from the original Mercury OptiMax 150-HP engine.

I have estimated the propeller pitch as follows:

Using the Crouch's Calculator, I got a top speed of 42.4MPH using these inputs:

HP = 150
LBS = 2700
Hull Factor = 180

The weight is estimated as 1700-lbs hull, 500-lbs engine, and 500-lbs for the kicker, trolling motor, fuel, fuel tanks, batteries, people. This might be too low.

Using the Prop Calculator, I got a 16.6-pitch using these inputs

RPM = 6000
Gar Ratio = 2.00
Slip = 10
MPH = 42.4

Based on these calculations I think a 16-pitch or 17-pitch propeller would be appropriate. Please comment

ASIDE:
I also tried a few other combinations of input variables.

[Moderator's note: a survey question seeking to discover how often this boat has been re-powered with this particular engine or a similar engine has been removed. I am certain that if there are readers who have first-hand experience with re-powering this boat in this manner, they will join the discussion and indicate that status, and that information will be more useful than discovering the number of readers that have the qualifications imposed.]

[jimh]

A good value for target boat speed with the new 150-HP engine would be the boat speed you have been getting from the existing 150-HP engine.

You could also derive the hull factor with the Crouch's Calculator if you had really accurate data for power, weight, and boat speed.

Q1: what is the propeller you have been running on the OptiMax 150-HP engine?

If that propeller is a Mercury propeller with a Flo-Torq hub, you can very likely re-use it with the new Yamaha F150XB engine by getting the proper hub adaptor. That would be a low-cost first-test of the new engine. You would then have some real data to use for making the next choice of test propeller.

[biggerstaff]

The top speed with the old engine was remarkably close to the calculated value of 42.4-MPH. That probably wasn't fully trimmed out, but I figured it was close enough. The previous propeller was aluminum, and I was not able to find a marking on it before I included it with the engine sale. I wanted to upgrade to a stainless propeller, anyway.

[jimh]

A three-bladed stainless steel propeller will likely be a very good choice. The Yamaha brand propellers are excellent, although priced accordingly. If you are buying a new Yamaha engine from a dealer and he is doing the installation, you can often get a sea trial of different propellers as part of the total re-power package.

I suggest you contact Ken at PropGods. He has a great deal of experience with many boat-engine combinations. He also sells propellers at reasonable prices, and will do some exchanges if a propeller you bought from him is not satisfactory.

[biggerstaff]

Jim, thank you very much.
I just got off the phone with Ken. He recommended a 17-pitch propeller [but unfortunately no other specifics mentioned here], which is right in line with the calculations shown above. As you mentioned, he is also willing to swap propellers for $40 which seems very reasonable.

[jimh]

Let readers know in a future follow-on post what propellers you test and which you bought.

[biggerstaff]

I bought a [POWERTECH three-bladed, stainless steel, high rake angle, light cup, model] PTZ3 14.25 -inch and 17-pitch from Ken at PropGods.

Boat Test Results

BOAT = 1999 OUTRAGE 17
ENGINE = 2022 Yamaha F150XB

DATE = March 2026
LOCATION = Lake Michigan
SEA STATE = small chop

Data recorded
ENGINE SPEED (assumed to be at full throttle) = 5,650-RPM
BOAT SPEED = 43-MPH
ENGINE TRIM = well out
TRIM TAB SETTING = 3 (of 10)

(Moderator's note: visit PropGod website at

https://propgods.com/product/ptz3/

for more information on this propeller. The indicated price is $400.)

[jimh]

Congratulations on doing a high-speed sea trial on Lake Michigan in March. I would expect the water temperature must have been in the 35 to 40-degree-F range. Testing in very cold water produces the best possible results due to the higher water density. Also the air temperature was probably rather cool, another influence that allows the engine to develop more power. The total boat weight is also a very significant influence on performance, including number of people aboard.

[biggerstaff]

Water temperature was 37 deg and air temp was in the 40's. Just me and my son aboard. We were able to boat a few coho and brown trout to get the season started!