CONTINUOUSWAVE

I just got a 1995 Outrage 19 and re-powered it with a 2019 Suzuki DF140A. The engine was broken in over six hours.

The propeller is a Suzuki three-blade 14 x 18-pitch.

At engine speed 3,000-RPM the boat speed is only 8-MPH.

At full throttle the engine speed is 5,500-RPM, and the boat speed is only 23-MPH.

I friend was on the boat. He feels the pitch on the propeller is wrong and needs to be changed.

I called Boston Whaler for a recommendation and they were no help.

I read some discussions saying this model boat does best with a 17-pitch and others saying 19-pitch or higher.

Give me advice on the boat performance.

Thanks,
Xavier

Who did the re-power?

Top speed 23-MPH is not good.

What engine was on the 1995 OUTRAGE 19 before?

What performance data do you have from the old engine?

The 1995 OUTRAGE 19 had s 1995 Evinrude 150HP V6 Ocean Pro.

The new DF140A engine was installed by a Suzuki dealer.

Xavier—

Is the DF140A engine still in the break-in period of zero to ten hours?

At what altitude are you boating?

What is the mounting height of the engine?

How far above the lowest possible mounting is the engine now installed?

Measure in units of 0.75-inch or “holes” from lowest possible position.

Please do NOT post the same query in multiple forums.

Your post in Repairs and Modifications has been deleted.

The boat is being used on Long Island Sound.

The engine has been broken-in, and it now has more than ten hours runtime.

I’ll look at the mounting height and get back to you.

The view of the engine in Figure 1 does not clearly show the mounting height.

The engine is likely mounted in the lowest possible position.

A four-stroke-power-cycle engine will typically only produce its rated power at maximum allowed engine speed.

Tell us the full-throttle engine speed range expected from the manufacturer specifications.

Tell us the engine gear ratio from manufacturer specifications.

Have you weighed the boat?

The performance so far is rather poor. The boat could be heavier than specification when new.

The DF140A is really a souped-up 115-HP engine, and all the extra horsepower will only come into play if the engine can accelerate to maximum engine speed, which will probably be over 6,000-RPM.

You should immediately try a 16-pitch propeller.

What is the engine shaft length?

The Outrage 19 II has a hull weight of 1900 lbs and a max hp of 150hp. It is the same hull design and max hp of the classic Outrage 18 but with the added liner and redesigned interior/console.

The DF140 has a WOT range of 5200-6200 rpms and a gear ratio of 2.59:1

You said "The engine was broken in over six hours."

The manufacturer recommendation is a 10 hour break-in period. Were the specific operating guidelines for hours 0-2, 3 and 7-10 followed?

Has WOT rpm ever been momentarily at 5800-6200?

I would have the engine mounted at least 2 holes up (top bolt in 3rd hole down from top). If not, consider raising the engine and re-tested.

With an estimated target speed of 40mph, the prop calculator shows a pitch recommendation of 18".

Remove the engine cowl and verify the throttle linkage is properly set. The cable at WOT should have the lever pushed all the way to the stop.

I have a 2003 190 Nantucket with a 2016 Suzuki DF140A. With a light load the boat can cruise 28-MPH and 4400-RPM and WOT IS 6,200-RPM at greater than 40-MPH.

The propeller a Suzuki 14 x 20-pitch three blade.

The engine is mounted three holes up. I understand Suzuki engines like to run high.

The hull weight is 2050-lbs.

I have a T-Top which adds more weight and drag.

The hull has no bottom paint.

Speaking of bottom paint; it looks like your bottom paint goes high on the transom:

Could there be unexpected weight in the stern?

LUCY—Something is totally not right. Need to take back to installer.

XavierMD1 wrote:I called Boston Whaler for a recommendation and they were no help.

Your expectation that Boston Whaler would have expert advice about the combination of one of their 25-year-old boats with a 2019 outboard engine made by a rival manufacturer to Brunswick’s Mercury engine that was never sold or tested or supported in any way by Boston Whaler seems a bit unreasonable to me, and to post your comment that Boston Whaler “was no help” seems totally unwarranted. Boston Whaler has been providing excellent support for their older boats.

If you just bought a new SUZUKI engine from a dealer, and the engine can barely get the boat on plane, you ought to be seeking help from the engine dealer, not from the company that made the boat 25-years ago.

I think you misunderstood my original post. I had no expectations only hope that Boston Whaler could start least tell me the size and pitch of the original propeller. They unfortunately do not have this information. Nevertheless, they were of help in pointing me in the direction of ContinuousWave as a resource for finding other Boston Whaler owners who might have repowered the same year/make/model for advice on proper propeller sizing. The people here have done exactly that and the invaluable information I received thus far is greatly appreciated.

XavierMD1 wrote:I think you misunderstood my original post. I had no expectations only hope that Boston Whaler could start least tell me the size and pitch of the original propeller. They unfortunately do not have this information.

I don’t think there was any misfortune. Boston Whaler likely did not sell their boats pre-rigged with an engine and a propeller in c.1995. That practice is now common, but, even if it were done in 1995, the propeller would not be particularly applicable to a 2019 SUZUKI engine. Outboard engines have different gear ratios and different propeller aperture dimensions.

You got the best possible answer from them: they had no expert advice on a propeller for the DF140A.

The approach to choosing a propeller is to first determine a target speed for the boat based on the hull design, the engine power, and the boat weight. Once a reasonable target maximum boat speed is known, a suitable propeller pitch is chosen based on engine speed, engine gear ratio, and an estimate of propeller efficiency with SLIP guessed to be 10-percent.

Using the method proposed by Crouch, a Boston Whaler hull assumed to have a hull factor of 180 and weighing 3,300-lbs, should be capable of 37-MPH top speed with a propeller shaft power of 140-HP. Again, these are all very reasonable assumptions.

Using a simple propeller calculator and this data for input

RPM = 6200
RATIO = 2.59
PITCH = 18
SLIP = 10

the calculated boat speed is 37-MPH. That seems quite reasonable for an 19 OUTRAGE II and 140-HP. The propeller now on the DF140A engine is not way off the mark.

There are likely only two reasons for the boat under discussion to be so much slower than expected:

—the boat weight is very much greater than 3,300-lbs, or

—the propeller shaft horsepower is much less than 140.

PHIL T’s comment to check the throttle opening linkage is good advice. The rigging of the throttle cable may not be opening the engine throttle to full-throttle. This would result in reduced engine power.

If you have modern NMEA-2000 instrumentation you can read the throttle position sensor data directly as the LOAD parameter. It should be above 95 at full throttle setting. If not, there was a sloppy job on rigging the new engine.

Some other factors that could affect boat speed:

—improper engine mounting height
—improper engine trim setting
—poor hull running surface such as fouling and marine growth
—very high air temperature, high humidity, high water temperature
—engine control system intentionally limiting engine speed
—fuel system rigging limiting fuel flow to engine
—propeller slipping on its hub.

For help with describing engine mounting height read the article at

ENGINE MOUNTING HEIGHT
viewtopic.php?f=7&t=739

and use the descriptive method given there.

You can also go to the Suzuki website and look at boat tests for that model engine. Though not exact it will give you a general guideline for what to expect performance wise with a similar hull.

Thanks to everyone for the great advice and input.

Let us know what actions you take to fix the problem