15 Striper Re-power: Mercury 60 EFI

Optimizing the performance of Boston Whaler boats
FISHNFF
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15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Tue Apr 12, 2016 9:58 pm

I sold my 1990 Mercury 50-HP three-cylinder engine with gear ratio of 1.61:1 and upgraded to a new Mercury 60 FOURSTROKE with a standard lower unit 1.83:1 gear ratio. [The Boston Whaler STRIPER 15 boat with new engine was] picked up yesterday and [I] cruised around for two hours on San Francisco Bay. I used the same 12-inch stainless steel Stiletto propeller. [Other gear aboard was] one battery, 9-gallons of fuel, and myself (at almost 200-lbs).

[Acceleration at full throttle from a standing start with the new Mercury 60 FOURSTROKE] was as good as the 50-HP two-stoke-cycle engine, if not better. [The STRIPER 15] seemed a bit less connected to the water. By this I mean [the STRIPER 15] feels a little squirrelly. [When the engine was] trimmed out [the STRIPER 15] wanted to chine walk, oscillating left and right.

I used the original gauges with an adapter. The tachometer read shy of 6000-RPM at 35-nautical-miles-per-hour boat speed. This [boat speed] seems about what the [STRIPER 15 made with the] old 50. The new 60 had more torque across the RPM range.

I did notice more water spraying up from the lower unit. At 4,000-RPM and medium trim I had a V-pattern spray that actually came slightly over the transom and sprayed up higher than the engine cowl. Looking down over the transom, I saw the water was coming from the front edge of the lower unit and I could not see the anti-ventilation [plate because] water was running over it.

The engine [mounting height] was [described engine mounting in terms that sound like the engine was mounted one-hole up from lowest position]. I had the dealer move it up one more mounting hole to [what sounds like a two-holes up mounting]. I haven't run it since.

[Please describe engine mounting height in terms of how many units of 0.75-inch or "holes" the engine is mounted above the lowest possible position. This method avoids misunderstanding about the engine mounting height.--jimh]

I'm skeptical that the tachometer reading is correct. I couldn't hear the engine over the wind noise, so I couldn't correlate engine speed by engine sound to the tachometer reading. The mechanic thinks that the engine never hit the rev limiter, which he thinks is 6,300-RPM, and I agree. I'm thinking [the engine] could use a bit more [propeller] pitch like 13 or 14.

With the 50-HP two-stroke-cycle engine, acceleration came on strongly, smoothly, and linearly to wide-open-throttle. With the 60, acceleration also came on strong, but the boat hull felt less stable. The throttle response was better with the 60. It felt like it had more on the top end. I'm hoping raising the engine will help with the instability.

I'm going to try a Yamaha 15-pitch black stainless propeller from my old Yamaha 50.

What do you think a four-blade stainless steel propeller will do?

I did 15 miles of cruising, idling, and circling around Alameda Island, and I barely noticed the fuel level went down.

FISHNFF

LCnSac
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby LCnSac » Tue Apr 12, 2016 11:13 pm

I have a somewhat similar setup, just east of you. 60 Merc Bigfoot, but it's a post-classic 2005 150 hull. I have the engine mounted level with the transom with [described mounting in what sounds like a one-hole up position]. The big difference is my propeller is a 14-pitch three-blade 12-inch stainless steel. With two on board and a fairly heavy casting deck just aft of the bow, I found 34-MPH easily and quickly, very comfortable, and probably could have hit three or more MPH more with trim adjusted to the chine walking stage. The rooster tail was nominal; anti-ventilation plate was where it should be when running, i.e., visible, and is about 1.5-inch above the lowest point in the transom. I believe this is an all-stock setup, and rigged by your dealer, OMS in Alameda. Given your narrative, and that you were hitting 40-MPH--which I think is beyond expectations for that boat and engine--and adding that my Bigfoot is geared lower than your Mercury, I think you may benefit from more pitch in the propeller.

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Thu Apr 14, 2016 12:16 am

Thanks LC for your information.

To anyone out there running [a Boston Whaler classic 15-foot hull] with a Mercury 60 FOURSTROKE, I would love to know what propeller you are running. Thanks. --FISHNFF

dgoodhue
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby dgoodhue » Thu Apr 14, 2016 9:07 am

An engine with 60-HP should push your classic 15-footer to 40-MPH. It seems odd the engine is spraying water and the [anti-ventilation] plate is under [water] if it's mounted two-holes-up. I would check the mounting. If it is mounted two-holes-up, is their a chance you were sold a 25-inch-shaft engine instead of the correct 20-inch-shaft engine?

goldstem
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby goldstem » Thu Apr 14, 2016 12:30 pm

A speed of 35-nautical-miles-per-hour IS 40-MPH, and he's doing just fine.

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Fri Apr 15, 2016 1:19 am

I thought [the spray from the gear case was] odd, too. The engine is a 20-inch-shaft engine.

I'm gonna run it again this weekend. I really liked the way the boat ran with the lighter two-stroke-cycle 50-HP engine. I'll get the right propeller dialed-in.--FISHNFF

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Mon Apr 18, 2016 12:51 am

The boat was launched at 5:45 p.m. local time this beautiful evening with just a bit of wave action on the bay with my two boys (age 17 and 14) wanting to cruise the bay after attending the Cherry Blossom Festival here in San Francisco where the temperature hit the low 80's. We ran across to Alameda.

The Yamaha 15-pitch black stainless propeller barely [allowed the Mercury 60 FOURSTROKE engine to accelerate to a speed of 5,000-RPM] with moderate trim. I let my boys take turns driving, so I didn't get to trim the motor way out. Speed was only 32.3-nautical-miles-per-hour. Acceleration at all speeds did not have that snap, but [the boat] was now running with 250-lbs more weight. Having the motor raised by the dealer (now two-holes-up) eliminated the water spray, and the propeller is running right at the top and the prop wash right down the middle looks right.

Tomorrow I'll be running around the Bay with a buddy with the 12-pitch Stiletto back on. Will see how stable she feels and what RPM the engine will turn.

FISHNFF

PJMSport15MY1984
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Mercury 60 EFI Repower

Postby PJMSport15MY1984 » Tue Apr 19, 2016 2:21 pm

Hello Fishnff

[Deleted sidebar discussion about a different engine]

If you don't trust your stock tachometer, hook up an auxiliary tachometer. As a result of this step, the next time you take the whaler out, you can compare both tachometers throughout the entire throttle level. This will tell you if your stock one is accurate.

The classic sport 15 is a small hull boat that is sensitive to weight. When you repowered with the current four stroke 60, where did you put the battery? I would put it opposite side of the console to try and balance these two items.

Where do you have your fuel tank?

These are all things you want to take into consideration in order to have a correctly balanced hull.

Now let us talk about speed. With your new engine and the correctly pitched propeller, you should hit 41 to 43-MPH with some trim and not much weight in the boat, and you should [accelerate from a standing start with full throttle] quickly. With a loaded boat, you should hit right around 33 to 35-MPH. You won't [accelerate from a standing start with full throttle] as quickly, but you should not have to work yourself or the motor to [accelerate from a standing start with full throttle].

Good Luck.
Paul

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Sun May 29, 2016 3:50 am

Now with [more than] 20-hours [of use of the new Mercury 60 FOURSTROKE], I can say that I actually like the old original [1990 Mercury 50 three-cylinder engine] better for driving.

The weight balance seemed much better as the boat felt more in control. At any trim angle or speed, the boat felt safe. With the new motor weighing 60-lbs more, the boat can feel unstable at higher trim setting. The hull tends to wander side to side. The speed is a shade faster than the 50. Other than that, the motor is great.

If I went with the Honda 50 with a weight closer the original Mercury 50, how would it perform?

FISHNFF

PJMSport15MY1984
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby PJMSport15MY1984 » Mon May 30, 2016 2:22 am

Fishnff

Honda lists their 50-HP outboard engines as 214-lbs or 223-lbs, depending on model. Your new four-stroke-power-cycle Mercury 60 is listed as 247-lbs. I have no idea what your old Mercury 50-HP tipped the scales at, so I can't give you any suggestions as to how it would compare with a new Honda 50-HP as far as handling or weight on your old SPORT 15 transom.

Have you analyzed how you are dealing with weight displaced in the hull of your whaler with your current power train?

You might want to do this first, to try and offset the weight of your new Mercury 60. Start by looking where your battery and fuel tanks are, and how close to the transom they are. The old SPORT 15 boats are very weight-sensitive little boats.

Paul

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Mon May 30, 2016 11:40 pm

When I first got my 15, I replaced the plastic portable 6-gallon tank that was thrown in the back with a 9-gallon tank mounted between the two pedestal seats. The battery was moved to the port side up against the rear of the passenger pedestal base. The small anchor is in the side console. That's it got weight for now.

The 60-lbs bow mount trolling motor and [two] 45-lbs marine batteries are put on for lake fishing. That would definitely shift the center of gravity.

FISHNFF

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Tue Aug 16, 2016 12:48 am

Update.

My engine got hit at the dock when I had it tied up to park the trailer. Big heavy aluminum tiller work boat crashed into the back. Bent and broke off corners of anti-vent plate. I ran the boat, and surprisingly there was no change. It still felt unstable at higher trim levels.

Now the boat is at a custom metal fabricator. My friend-owner is making a foil or fin to hopefully eliminate high speed instability.
It's going to be one-piece, 12-inch wide, extend 2-inh rearward, taper narrower toward the front and bow, and have edges turned downward. It's going to be mounted on the bottom of the anti-vent plate.

The installing dealer can't figure out why the boat loses stability at higher speeds and higher trim angle.

Why does a 2016 Merc 60 EFI (247-lbs) run unstable and chine walk at 35 to 40-MPH when turning a Stilleto 10.5 x 12 propeller, while a 1989 Merc 50 three-cylinde (188-lbs) running the same speeds and propeller runs rock steady stable at all trim angles?

I've run the boat with both engines with one or two or three people aboard with same results. I even tried Stilleto 12 x13 propeller: less [boat speed], less [engine speed], and same instability.

Boat and engine should be ready this week with a new Smartcraft tachometer, a fuel meter, a troll control, an hour meter, and a new custom fin. Will report then.

FISHNFF

jimh
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby jimh » Tue Aug 16, 2016 8:07 am

Since the new engine has added 60-lbs to the transom, that may have influenced the hull's performance and handling.

flymo
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby flymo » Sun Aug 21, 2016 12:09 pm

The two factors which combine to create your situation seem quite obvious from your previous posts:

--the new engine is able to move the boat faster

--the new engine is heavier

With those changes, at speed and at high trim angles, you are riding on the stern more than previously, so the lifting strakes on your 15 are out of the water. On a 15 the strakes do not extend all the way to the stern--a design flaw in my mind--and the boat is riding on the rounded part of the hull only, with no lateral stability at all in that condition. Most 15 owners who run maximum horsepower are familiar with this situation.

The solution is to move weight forward, or change to a stern-lifting propeller. If you are using a Stiletto Advantage it is lifting the bow and exacerbating your problem. Go to a propeller with less rake and you'll probably be OK. Skip the custom fin. It will solve the problem by slowing you down and cutting into your mileage, but that's hardly a great solution.

Flymo

El Rollo
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby El Rollo » Wed Sep 07, 2016 2:25 pm

Great thread, and the reply [above from] Flymo is spot on.

I completed a full restoration and customization on a 1988 Super Sport. I re-powered with a Yamaha F70. One of my main goals during the process was weight savings along with simplicity. By the end of the project, I had still added weight to the boat.

I ended up with a Turbo [FX-4] 13-1/4 x 14 stainless propeller. The Turbo [FX-4] 13-1/4 x 14 stainless propeller gave quicker time-to-plane, better low-range and mid-range throttle response, enhanced low-speed maneuvering around docks, a good amount of stern lift, and some loss of top speed.

[After a rather lengthy sidebar discussion, now deleted, it was determined that the propeller being recommended was the TURBO PROPELLER model FX-4 four-blade propeller designed for smaller gear cases and in the pitch and diameter noted above--jimh]

I had originally used a Yamaha Performance Series three-blade 16-pitch stainless propeller. While the top end speed was significantly higher--not sure by how much--the stern lifting and resulting better ride qualities of the four-blade, made the swap a no-brainer. I haven't tested [boat fuel economy], but it seems the four-blade contributed to some loss in MPG. The three-blade made for a much wilder ride in all but clean and calm water. But the bow oscillation in choppy water was no good.

I also installed a Bob's 5-inch manual jackplate, which really is nice to use in setting up the boat for each propeller. I haven't taken the time to really dial-in jackplate height exactly for each propeller, but I plan to. Then I will have the propellers balanced and tuned for optimal performance.

The 15-footers are great boats, and it's nice that you can maximize your set-up for your personal needs.

Lastly, I ran in a 15 that was powered by a Honda 50 four-stroke and had a 5-inch jackplate. It was a really nice set-up due to the light weight of the engine. It was set-up for fishing with a trolling motor, live-well, three batteries, fish finder, seats, etc. A good amount of additional weight was put in the boat, but it still got 36-MPH with two adults on board.

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Sun Oct 02, 2016 12:27 am

Results are in. I was able to run the boat with a newly-added, custom, aluminum fin attached to the anti-ventilation plate.

Day 1.
Freshwater
2 persons
70-lbs thrust bow mount trolling motor
2 Group-24 batteries in bow
9-gallons fuel between pedestal seats
1 Group-24 battery under passenger seat.

RPM 5950
Speed 32.4 nautical-miles-per-hour in a dead end slough at slack tide

No porpoising. Mild instability at WOT trimmed out crossing wake.
No bow rise.


Day 2
Saltwater
1 person
9-gallons fuel between pedestal seats
1 Group-24 battery under passenger seat

RPM 6070 to 6120
Speed 35.4 -35.6 nautical-miles-per-hour. Slack tide along pier both ways
No porpoising
Trimmed for maximum speed, I could get boat to walk back and forth if I crossed waves at a certain angle. Trimming it in and slowing down stopped the motion. Calm water, no problems. Keep trim level, no problem.

Much better handling with the fin than without.
Without the fin I could trim it out at WOT and have the boat dancing back and forth. Scary.

The fin runs right at the top of the water, meaning the top of the plate is out of the water except for some spray.
Pops right up on plane with almost no bow rise, with or without a load.

Bottom line: the fin works in this case.
The Mercury 60 FOURSTROKE running a 10.5 x 12" Stilleto
Mounted two-holes-up

Simon
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby Simon » Mon Oct 03, 2016 3:06 am

Sounds like you're getting that boat dialed-in. That's admirable.
1987 15' Sport CC

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Thu Oct 13, 2016 11:48 pm

I have put a few more hours on [the Boston Whaler STRIPER 15 with Mercury 60-HP engine] rig. I ran [the STRIPER 15] down to Pescadero Beach from Pillar Point Harbor, Half Moon Bay, about 18 miles, and [the Mercury 60-HP engine] burned 2-gallons per the Smartcraft gauge. Then I ran [the STRIPER 15] around, fished for 3-hours, and ran back at 23 to 25 nautical-miles-per-hour in slightly bumpy seas; [the Mercury 60-HP EFI engine] burned 5.8-gallons.

The [STRIPER 15] ran very well. The [Mercury 60-HP EFI] engine never misses a beat, except:
--it made a slight squeal noise (from a belt perhaps)
--it made a smoke puff for three to four seconds every time it started.

Is [the smoke puff for a duration of three to four seconds during engine starting due to] the fuel enrichment adding more gasoline? I thought only carburetor engines did that.

FISHNFF

jimh
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby jimh » Sat Oct 15, 2016 10:31 am

That you can run in the open Pacific Ocean in a 15-foot skiff at almost 29-MPH for long distances is quite impressive, particularly since you described the wave conditions in the Pacific Ocean as "bumpy seas." Having had a 15-foot Boston Whaler boat, I found that running at 29-MPH would require almost flat calm conditions. We never ran the boat in the ocean, but did venture out in the Great Lakes when the waves were very small.

alloyboy
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby alloyboy » Sat Oct 15, 2016 10:52 am

FISHNFF wrote:Is [the smoke puff for a duration of three to four seconds during engine starting due to] the fuel enrichment adding more gasoline? I thought only carburetor engines did that.FISHNFF

An EFI motor will also enrichen the fuel mixture during a cold start, similar to what a carburetor model will do, but I don't think this is your problem. Excessive fuel will be blackish smoke. Excessive oil will be bluish smoke.

If a four stroke is left trimmed down then over time a bit of oil will migrate past the piston rings and get into the combustion chamber. The motor will then emit puff(s) of smoke when next started. To see if this is the situation with your motor try trimming the motor up a bit when it is not being used. See if this mitigates the smoking concern.
oil smoke.png
oil smoke.png (72.59 KiB) Viewed 32512 times

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Mon Oct 24, 2016 4:46 pm

Thanks for the oil seepage remarks. I don't think they applies because the smoke will occur each and every time I start the motor, whether it sits ten seconds, ten minutes, or ten days. And the smoke does not look blue. And it is not steam.

I am inclined to think it is a little extra shot of fuel is the cause. Not a big concern, just an observation. I'll check with the dealer.


And yes, the boat runs great in slightly bumpy weather. Level trim, maybe slightly negative, keeps it from fitting airborne. There was a very big groundswell, and the seas were a bit bumpy, but slight wind.


FISHNFF

jimh
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby jimh » Tue Oct 25, 2016 6:54 am

ALLOY--that is a very interesting observation regarding oil getting into the combustion chamber based on the orientation of the engine after shut down. Thanks for that information.

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Tue Apr 11, 2017 2:36 pm

I started to run the boat this season. Full load of three batteries, 24-Volt bow-mount trolling motor, nine gallons, and two adults. Oil change with MobilOne 10w-40. [Boat speed is] 33.4-Nautical-Miles-Per-Hour. I could trim out to 6,190 RPM. [Boat] speed from 6000 to 6190 was unchanged.

I read about someone running a Spitfire four-blade 15-pitch aluminum propeller on a Mercury 60 on a 15 Striper and was getting low 40's on speed. Anyone remember this? I can't see turning a 15-pitch on a standard gear case. I'm thinking of trying a 14-pitch Spitfire Aluminum.


FISHNFF

Simon
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby Simon » Wed Apr 12, 2017 11:49 am

What's the configuration on your boat? I have a 15CC with F70 and running on 17 [pitch] aluminum prop. I have three batteries under the seat and fuel tank in the console. The weight of the console and tank really helps with trimming the boat. I run full 18 gallons all the time with 24-Volt trolling motor on bow. I'm able to get 42-MPH with two adults and full gear with trim. I'm guessing you're almost there. Perhaps look into a stainless propeller.
1987 15' Sport CC

jimh
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby jimh » Wed Apr 12, 2017 7:25 pm

It is hard to compare data when one set is in MPH and the other set is in Nautical-Miles-Per-Hour.

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Thu Apr 13, 2017 9:44 pm

A boat speed 33.4-nautical-miles-per-hour is 38.4-MPH. The Stilleto propeller in it now is stainless

A while back a friend had a Skeeter F-80 Strata bass boat with an 80 Mercury three-cylinder. He had best results with an aluminum propeller. I can't remember how many and what types he tried, and I know diameter, pitch, rake, cupping all make a difference. His bass boat was 15-feet 1-inch and ran in the upper 40's. It blew the doors off of a 15 Striper with a 70 Evinrude.

Still looking for info from anyone running a similar combo of a 15 Whaler Classic and a Mercury 60 FOURSTROKE with a Spitfire aluminum propeller.

FISHNFF

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Fri Apr 14, 2017 11:35 pm

A boat speed 33.4-nautical-miles-per-hour is 38.4-MPH. I'm still trying to [wring] some info on someone with a Mercury 60 FOURSTROKE with standard gear case on a classic 15 turning a Spitfire propeller. Thanks--FISHNFF

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Sat Jan 06, 2018 11:18 pm

I purchased 14-inch Mercury Spitfire 4-blade aluminum propeller, and I decided to go run it on the Bay. First impression there was no gear clunk putting the boat into gear. Advantage #1.

Next was the acceleration. Much better than the Stilleto 12-inch Stainless. The acceleration felt more like the two-stroke 50 that was originally on the back. Advantage #2.

Throttle response, while related to acceleration, is almost instantaneous. If cruising along at 20-MPH and you hammer the throttle, you feel it. Advantage #3

The propeller never blew out when trimming extremely high and held tight when making sharp turns.

Now here is the surprising thing. Moving from a 12-inch three-blade Stilleto stainless to a 14-inch four-blade aluminum Mercury Spitfire netted faster acceleration and higher engine RPM. In fact the tachometer was banging on the 6,250-RPM rev-limiter. The speed dropped to 32.5-nautical miles per hour. I couldn’t find an area without current, but the boat is definitely a tad slower.

A 15-imch Spitfire was recommended by someone on another forum, but I thought it would be too much. Guess he was right. Even speaking to a Mercury tech on the phone said 14-inch tops.

So, there it is. I’ll try a 15 next and report back.

Today there were two persons on board, no trolling motor, batteries or fish. Just a bay cruise.

FISHNFF

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Mon Apr 02, 2018 12:50 am

In my quest for the perfect prop, I found the Stiletto Triad 3.5 in 10.25-inch diameter and 14-pitch.

I ran the boat at Lake Berryessa with

--two aboard,
--three batteries,
--nine gallons fuel. and
---24-Volt bow-mount Minn Kota.

Acceleration was moderate and smooth but acceptable.

When the engine was trimmed-up, the boat remained stable. Maximum trim could be reached without [the propeller] blowing out.

[At an engine speed with the Mercury 60-HP FOURSTROKE of] 5950 to 6000-RPM [the boat speed was] 34.5 to 35.2 nautical-miles-per-hour running multiple directions. That’s 40-MPH, and the boat felt great.

That is it--I have what I believe is the best setup.

So now I have for sale
--14” Spitfire 3 blade aluminum with hub.
--12”x 13” Stilleto 3 blade with rubber hub for Merc
--12” Black Max 3 blade aluminum unused

Thanks all
FISHNFF

El Rollo
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby El Rollo » Fri Apr 06, 2018 1:06 pm

Great numbers. Sounds like you have it dialed.

FISHNFF
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Re: 15 Striper Re-power: Mercury 60 EFI

Postby FISHNFF » Sun Nov 14, 2021 2:25 am

Update [to the five year old thread.]

I swapped out two Group-24 deep-cycle cycle lead-acid batteries for a single 24-Volt Lithium Iron Phosphate battery to power my bow mount trolling motor.

Removing 60-lbs from up front does wonders with acceleration and handling. The boat would exhibit some porpoising if trimmed out, but no longer. Boat speed increased almost 1-MPH.

[The Mercury 60-HP FOURSTROKE engine] had an intermittent rough idle. A dealer thought [the cause was a part called the] Idle Control Valve. [The dealer is located] a bit far from where the boat is stored. and the dealer service department was swamped; I just ordered an Idle Control Valve. To [remove the old Idle Control Valve and install a new Idle Control Valve in the Mercury 60-HP FOURSTROKE was a] five-minute swap, and the engine has never ran so well.

I guess the [problem of the intermittent rough idle had] progressed slowly. Now there is no sputter or bogging down.

ASIDE: Lake Berryessa is about to turn over. I will be putting hours on [the Mercury 60-HP EFI FOURSTROKE engine] again.

FISHNFF