1998 Outrage 17 II with Yamaha F150XCA

[MisChief15]

[Moved to PERFORMANCE for discussion. All topics asking for advice about propeller selection are in PERFORMANCE, not in THE GAM.--Moderator]

After reading a lot of re-power topics on this site for the Outrage 17 II with lot of useful information from Jimh, Phil, and others, I decided to re-power my 1998 Boston Whaler Outrage 17 II with a Yamaha F150XCA (the DEC - digital control version) weighting around 487-lbs for the 25-inch-shaft model. I just want a new reliable engine to have some good times on the water.

About the boat set up and total weight estimation for propeller selection:
1. Lenco 9x9 edge trim tabs
2. Either a Yamaha 9.9HP kicker motor or a a suzuki 2.5 HP (the shop advice that the f150 is very reliable that i may not need the 9.9)
3. LiveBait set up from the well under the quarter seat on the port site.
4. Two batteries in the Console.
5. Fishing gears, and electronics.

I think I will go with the Yamaha SDS stainless steel propeller.

[Inferred request: give propeller recommendations for an OUTRAGE 17 II with a Yamaha F150XCA engine.]

[Phil T]

I do not have any SDS prop recommendations from owners for that engine-hull combination.

I do have the following:

Yamaha 14.25 x 18 Performance
Reliance 14.25 x 17
Mercury 14 x 18; or 19-pitch with engine three-holes-up.

I would consider going down in pitch 2-inches due to the weight.

A four-bladed proepller would help acceleration from a standing start and would keep you on plane better given the added weight.

Get advice from and buy the propeller from Ken Reeves at Prop Gods.
http://www.propgods.com

[MisChief15]

Thanks Phil, I think I will ask the shop try the Yamaha Reliance 14-1/4 x 17 first and see how it goes.

[jimh]

Q1: what is the gear ratio of the F150XCA engine?

Q2: what is the recommended optimum engine speed range at full throttle for the F150XCA engine?

Q3: what was your calculated estimate of total boat weight for normal operation?

Q4: do you have ANY performance data about the boat with whatever engine is on there now?

If the answer to Q4 is yes, then please provide that data.

[MisChief15]

Thanks Jim,

A1. The gear ratio of the F150XCA engine is 2:1

A2. The recommended optimum engine speed range at full throttle for the F150XCA engine is 5500-6000

A3: My calculated estimate of total boat weight for normal operation: 3,100 lb to 3,450 lb

Dryhull (1700) + Motor+Control + small kicker(485+40 +40) + trim-tab(20) + small live-bait well(30) + anchor(20)
+ electronic/fishing gears (100) +2-4 guys (300-700) + fuel (300 lb for about 50 gal)

A4: I have very limited performance data about the boat now with the mercury 115.
I run about 38mph at 5700 rpm with 13-3/4x15 Prop, half fuel tank, only 1 person, and other gears of 200lb.

I just dropped off my boat at the shop on Friday, and will take them a week to complete installing the motor, and some other add-ons i asked them to do.
thanks all.

[jimh]

Based on a boat weight of 3,100-lbs, an engine power of 150-HP coupled with an efficiently-operating propeller, and a hull coefficient for 180 (typical for moderate V-hull planing boats such as the OUTRAGE 17 II), the predicted maximum boat speed is about 39.6-MPH. The prediction is from the Crouch Planing Speed Formula.

Assuming an engine speed in the middle of the recommended range at 5750-RPM and the 2:1 gear ratio, in order to obtain 39.6-MPH with a propeller having a SLIP of 10, the propeller pitch would need to be 16.7-inches. The prediction is from my own propeller calculator.

You can juggle the parameters like hull weight as inputs for the Crouch Planing Speed Formula. I have implemented the formulat in a calculator I designed at:

https://continuouswave.com/calculators/crouchCalc.php

For example, if boat weight increases to 2,400-lbs, speed decreases to 37.8-MPH.

You can juggle the RPM and SLIP parameter to see how it affects SPEED and PITCH using the Propeller Calculator I designed which lets you enter any four of the five variables and calculate the missing fifth variable.

https://continuouswave.com/calculators/propCalc.php

For example, if SPEED is reduced to 37-MPH (form a heavier boat weight), and SLIP is increased to 13, the PITCH reduces to 15.6-inches.

[jimh]

Re the current engine and its boat speed:

Using your stated performance with the present 115-HP engine as producing 38-MPH speed, I can infer the total hull weight was only 2,580-lbs (using 180 as the hull coefficient).

Changing to 150-HP and adding maybe 120-lbs for the bigger engine gives 2,700-lbs for hull weight and predicts a speed potential of 42.4-MPH.

Looking for a propeller pitch for
MPH = 42.4
RPM = 5,750
RATIO = 2.0
SLIP=10
calculates PITCH = 17.3-inches

For initial testing with the 150-HP engine, select a 17-pitch propeller.

[MisChief15]

Thank you very much Jim your you calculator and analysis.

[MisChief15]

Re the current engine and its boat speed:

Using your stated performance with the present 115-HP engine as producing 38-MPH speed, I can infer the total hull weight was only 2,580-lbs (using 180 as the hull coefficient).

Changing to 150-HP and adding maybe 120-lbs for the bigger engine gives 2,700-lbs for hull weight and predicts a speed potential of 42.4-MPH.

Looking for a propeller pitch for
MPH = 42.4
RPM = 5,750
RATIO = 2.0
SLIP=10
calculates PITCH = 17.3-inches

For initial testing with the 150-HP engine, select a 17-pitch propeller.

Hi Jim--I am happy to report back that this estimate from yours is RIGHT on. I am almost done with the suggested 10-hours break-in on the new Yamaha F150XCA engine on the 1998 OUTRAGE 17 II boat. On the last run, I ran the boat in the San Fransisco Bay--where it was not too calm nor too rough--and, for the first time with the new engine, I pushed the throttle to wide-open for a few short bursts. I recorded these numbers:

RPM = 5800
MPH = 42.5

For this test the boat was fairly unloaded, and I used some bow-down on the trim tabs. I will report more results as I do more testing. So far, I am very happy with the results of re-powering with the new engine.

Thanks

[jimh]

That the Crouch Speed Prediction method was quite accurate in your particular case is very good to know. The method has shown itself many times to be quite good at speed prediction.

You did not mention the propeller, but earlier you stated your intention to get the Yamaha Reliance 14-1/4 x 17 propeller. Please confirm that was the propeller tested. It sure sounds like it was from your engine speed and boat speed data.

[Phil T]

Verify the engine is rigged at the appropriate height.

[The engine should be mounted two-holes up; see the illustration in the pinned article above on transom mounting height nomenclature for illustrations that show the location of the top engine mounting bolt.]

What is the propeller make, model and size you installed?

[MisChief15]

The propeller is the Yamaha Reliance SDS 14 1/4 x 17 (part number 68F-45972-20-00).

When I brought my boat to the shop, I did mention [that I wanted the engine to be mounted in the two-holes-up position] but the technician said [mounting the engine at two-holes up] would be too high. With this outboard, there are only four holes [instead of five holes] to choosef rom for [the] top mounting [bolt position], and I see that if the [the two-holes-up mounting were used then the engine] would be [mounted] too high.


I am really glad that I decided to add Lenco 9x9 Electronic Trim Tabs as they really helps this hull.

Fig. 1. This view of the transom shows the engine mounting height is One-Hole-Up, and also shows the location of the LENCO 9x9 trim tabs, which are mounted rather close to centerline, with tab inboard end abutting the thicker section of the transom.

transomView.jpg (41.08 KiB) Viewed 20748 times

[jimh]

When I brought my boat to the shop, I did mention [that I wanted the engine to be mounted in the two-holes-up position] but the technician said [mounting the engine at two-holes up] would be too high. With this outboard, there are only four holes [instead of five holes] to choose from for [the] top mounting [bolt position], and I see that if the [the two-holes-up mounting were used then the engine] would be [mounted] too high.

Your comment does not make sense. Using the two-holes-up mounting with either a four-hole engine mounting bracket or a five-hole engine mounting bracket puts the engine at the same height.

Also, I changed ALL mentions of engine mounting height to use the standard nomenclature of number-of-holes-up from lowest-position, and NOT describe the engine mounting by arbitrarily giving numbers to the holes what are not numbered. Inventing hole numbers just leads to confusion because there are no numbers on the holes, and there is no basis to always assume that everyone is counting in the same direction, that is from top-to-bottom or bottom-to-top, which is why using that approach just creates ambiguity and confusion and that is why it is never used on this forum.

[jimh]

I am really glad that I decided to add Lenco 9x9 Electronic Trim Tabs as they really helps this hull.

You seem to have mounted the trim tabs as close as possible to centerline, which limits the effectiveness of the tabs. The farther out from keel centerline the tabs are placed, the more effect they have on balancing lateral trim. With close to keel centerline mounting, the tabs probably work fine for adjusting the fore-and-aft trim (raising or lowering the bow), but they won't be as effective on side-to-side (port or starboard lean) trim.

Did you get advice from LENCO about the tab mounting position on the transom in terms of how far outboard from keel centerline would be the best fit?

Note: a REFERENCE article discusses options for trim tab mounting. See

https://continuouswave.com/whaler/reference/trimTabs.html

[jimh]

The propeller is the Yamaha Reliance SDS 14 1/4 x 17 (part number 68F-45972-20-00).

Thanks for verification that the propeller used was the one you mentioned earlier in the thread that you intended to buy.

Entering the following parameters into my propeller calculator to find the value of SLIP:

RPM = 5800 (from your test data)
RATIO = 2.00 (from the engine manufacturer)
PITCH = 17 (as marked on the propeller)
MPH = 42.5 (from your test data)
results in the calculated value for SLIP as
SLIP = 9.0

A value for SLIP of 9.0 is a good indicator the propeller is working effectively.

[MisChief15]

I did not consult with Lenco about the location [of the trim tabs]. The location was chosen mainly so that it doesn't interfere with trailer [bunks] on both sides.

[Jefecinco]

When fully retracted trim tabs should be as close as even with the hull bottom as practicable. They should not interfere with the trailer bunks if properly mounted anywhere on the transom.

Do your electric trim tabs retract when the ignition is turned off?

Repositioning the trim tabs to a more outboard position over the winter would be an easy project if after using them as is for a few weeks indicates any value in moving them.

When it comes to re-sale a more usual trim tab mounting would be helpful.

[jimh]

In Figure 2, below, the trailer bunks appear to be extending well past the boat transom.

Fig. 2. The trailer bunks appear to extend well past the transom, or in another aspect, the boat has been positioned too far forward on the trailer.

trailerBunkInterference.jpg (67.82 KiB) Viewed 20462 times

Do the trailer bunks actually extend past the transom, and if so, by how much?

Generally there is not much value in having the boat position on the trailer so that the boat transom ends up being pulled so far onto the trailer that the trailer bunks are extended farther aft than the transom.

To base the location of the trim tabs on the basis they would be liable to strike the trailer bunks when the boat is loaded on the trailer because the boat must be hauled forward and onto the bunks is not the best criterion for where the trim tabs ought to be placed.

It would be simpler to reposition the boat on the trailer so the transom was at the end of the bunks, or even to cut off a few inches of the bunks so they did not extend farther aft than the transom.