posted 02-12-2008 03:55 PM ET (US)            

Here is what he said
Propping Correctly
It is vital to your engine’s long term health that you be propped correctly and yes, many mfr’s
don’t get it right. Many Mfr’s supply you with a “Mirage” propeller which is Merc’s worst prop, IMO.
Having the wrong propeller is like running around town in your car in 3
rd gear from stoplights.
Verados that are “over propped” - low RPM at WOT – have been known to “make oil” that is add raw fuel to the crankcase which raises the oil level over a period of time (BAD)…
1. Load the boat down with 50% gas and a light load for fishing, cruising, etc
2. Find a very flat piece of water a mile long and bring your trim tabs all the way up.
3. Trim your engines "in" and take it up to full WOT and start trimming up
4. Keep trimming up until the engine starts cavitating - losing speed (you can't hurt it - all new
engines have rev limiters)
5. Now drop it back down a bit until it "bites"
6. Now look at your rpm - For Verados it should be at least 6000, 6250 would be ideal.
compare the results on a propeller slip calculator - from cruise on up to WOT you should be less
than 10%---> go here: http://www.rbbi.com/folders/prop/propcalc.htm

posted 02-12-2008 05:08 PM ET (US)            

I only get about 5500 doing all that he mentioned. At the NY Boat Show I spoke with a Merc rep, and rather than the 15p Rev4 he suggested an Enertia in the same pitch I already have 17". I'm confused.
But he said I may be able to trial a propeller free.
And the Merc link for propeller selection has been broke for the longest time keeps telling me my expected speed or pitch is incorrect.

posted 02-12-2008 08:08 PM ET (US)            

We should stay in touch on our efforts to find the perfect propeller given that we have identical boats and engines.

posted 02-13-2008 12:12 PM ET (US)            

Full fuel versus the recommended half fuel in your 21 Ventura is like having an huge NFL lineman standing behind the helm area.

it makes no difference which way the current is going unless an opposing wind is kicking up a significant chop.

Please let us know what you find. I'm going to be testing my new Whaler which will be delivered with full fuel.

posted 02-13-2008 04:00 PM ET (US)            

read this twice..it'll take a few min to download

http://www.veradoclub.com/images/Verado_Owner_s_Tips__3_.pdf

posted 02-18-2008 07:24 PM ET (US)            

quote:

---

"There has been some discussion in other posts about a new generation Verado in 2008."

---

Mercury does not use model year designators. There was a distinct change in the Verado motor which occurred in mid-year of 2007. There is no way to differentiate the new motor from the older design except by the cowling graphics. Otherwise all the nomenclature used by Mercury for the engine seems to be the same. The "dock name" for the newer motors is "GEN 2" as in generation two, or second generation. The cowling graphics have a raised chrome look.

The precise differences between the Verado and the Verado GEN 2 have not been well documented, at least as far as I know, but one significant difference which has been widely noted is that the GEN 2 motors seem to have better fuel economy but a "worse" emission rating compared to the initial models. I put "worse" in quotes because the GEN 2 motors are still approved for sale in all states except California. However, in California they are being sold under the fleet average provisions of the California emission regulations which measures a brand's total product mix and its total emission output. So even though the individual Verado motor does not meet the emission rating in California, it can still be sold there as long as not too many of them are sold there. Solution of this problem of exactly how many can be sold in California will require some calculus, and I will leave that to the California regulators, the Mercury emission certification engineers, and the lawyers.

There seems to be a general linkage between improved fuel economy and increased emission levels (or "worse" emissions). That is, an engine which has been tuned to produce the absolutely lowest possible output of the regulated combustion products may not be able to produce fuel economy which is as high as possible if the engine were re-tuned for best fuel economy. This seems to be what has happened in the case of the GEN 2 Verado motor. The GEN 2 Verado will get better fuel economy than the original motor while emitting more combustion products in its exhaust gases. For most boaters this is an acceptable situation, even probably for Californians. For everyone else, it is a no-brainer. Give me better fuel economy, thank you. I imagine you will agree.

Regarding reliability problems, the Verado motor was introduced in February of 2004 and it did not ship in large numbers until later in that year. So we have had about three and a half years of production and field experience. In that time there have been very few reports of any problems with the Verado which have not been resolved to satisfaction. I believe that a few problems have been reported with the engine mount during extremely high speed transit in high seas, but those were very exceptional cases, and most boaters would never run their boats at those speeds in those conditions, so it was not particularly a Verado problem but more of a crazy boat driver problem.

I do not see anything about the Verado motor which would make selection of an appropriate propeller particularly different than in any other outboard motor. I do not think that the Mercury MIRAGEplus propeller is "the worst" propeller in the Mercury line, and I reject that notion. When the Verado motor was first introduced the Mercury propeller line did not have a REVOLUTION4 propeller with a pitch that was low enough to be used in some cases where a single Verado was powering a large boat. Later Mercury introduced a REVOLUTION4 propeller in 15-inch pitch, and this has become a popular choice for some boat and motor combinations involving a Verado.

My impression of the propeller testing done by Boston Whaler for their particular boat and engine combinations is that it is generally quite comprehensive, although limited to Mercury propellers--which, since Mercury makes 700 different propellers, is by no means particularly limited. For someone to characterize the propeller testing done by Boston Whaler as being " a compromise" I would suggest that all propeller selection is a compromise, and what is perfect for your application may not be perfect for another owner's application. But I completely reject the suggestion that Boston Whaler was deficient in propeller testing or sold you an inferior propeller because the boat has a MIRAGEplus propeller. That is just nonsense, and when I hear nonsense I will point it out.

The advice about propeller selection given above as being specific for a Verado is really just the usual general advice for selecting a propeller for any boat, and I don't find it particularly specific for a Verado and a Boston Whaler. The recommendation that propeller selection should permit an engine to reach the upper range of its rated maximum engine speed when a boat is lightly loaded and properly trimmed is applicable to all boats and motors, inboard, outboard, Mercury, Yamaha, two-cycle, four-cycle.

posted 02-18-2008 07:49 PM ET (US)            

I have tested a REVOLUTION4 and a MIRAGEplus of the same pitch (17-inch). The difference in maximum engine speed on my test was quite significant.

MIRAGEplus = 5,400-RPM

REVOLUTION4 = 4,700-RPM

posted 02-19-2008 09:42 PM ET (US)            

The initial premise was that going from a MIRAGEplus of 17-inch pitch to a REVOLUTION4 of two-inches less pitch would result in a net INCREASE in engine speed. I would be surprised if that result was obtained.

The general rule of thumb with propellers is that in a line of propellers of similar design, decreasing the pitch by 2-inches will produce about 450-RPM of engine speed increase, and vice versa.

posted 02-19-2008 10:56 PM ET (US)            

Jim, love ya, but honestly if you never propped a verado, why expound on it?

posted 02-19-2008 11:13 PM ET (US)            

You can see a graph of my propeller power curves for those two propellers in my article on that subject:

http://continuouswave.com/whaler/reference/propellerPowerCurve.html

If we had a power curve for a Verado engine we could predict the engine speeds by seeing where the curves crossed.

Glen--sorry if I didn't immediately think to put in a plug for one of the sponsors of your website. It did not occur to me.

posted 02-20-2008 11:16 AM ET (US)            

For the record, here are the maximum engine speeds for each propeller:

Revenge 25 WT with twin 1989 Mercury 150 HP:

17" Revolution 4 -- 5900 RPM
19" Revolution 4 -- 5400 RPM
19" MIRAGEplus -- 5500 RPM

Mako 215 with 1994 Mercury 225:

19" Revolution 4 -- 5300
19" MIRAGEplus -- 5600
21" MIRAGEplus -- 5000

posted 02-21-2008 12:01 AM ET (US)            

In your data the REVOLUTION4 turns about 100 to 500 RPM slower than the same pitch MIRAGEplus. Therefore, if the REVOLUTION4 had its pitch dropped by 2-inches, the engine speed ought to tend to increase by 450-RPM. The net would be (450 minus 300 or) about a 150 RPM increase compared to the higher pitched MIRAGEplus.

If anyone has a REVOLUTION4 in 15-inch pitch, I would love to test it.

ASIDE: When we were at the Boston Whaler Owner's Event at Torch Lake last summer, there was a new CONQUEST sitting on the lot on a trailer. It had a Verado with a REVOLUTION4 15-inch pitch propeller. I was very tempted to ask the dealer if he would mind if I took the propeller off the new boat and did a quick propeller test run with it, but I did not have quite enough chutzpah to ask him.

The REVOLUTION4 15-pitch seems to be a popular set up on larger boats rigged with a single engine.

posted 02-21-2008 10:29 AM ET (US)            

Mako 215 with 1994 Mercury 225:

posted 02-21-2008 01:59 PM ET (US)         

25 Outrage, with Armstrong bracketed twin Mercury 200 EFI's, 1.87 gear ratio, counter rotating. This is a relatively high power to weight rig, and the twin Rev-4's give the hull great lift, better than the other lines of props.

23" Laser II -- 5600

21" Laser II -- 6000
21" Revolution 4 -- 5900 (lg vent plugs, FT IV hub, 62MPH)
21" Mirage Plus -- 5600

19" Revolution 4 -- 6300

My thoughts: Rev-4's really turn on when they are driven by twin HIGH power engines, mounted high, on lighter boats where the twin props can achieve the overall hull lift, greatly reducing drag, and increasing top end speed. I would not recommend a Rev-4 on a single engine low power-to-weight boat, instead preferring a Vensura 4-blade, Vengeance (surprisingly good prop) or Mirage Plus.

On my boat, I actually think a pair of 23" Tempest Plus or Enertia's would provide even higher top end.

Here's some more data:

21 Ribside Outrage, single Merc 2.0 liter 150, 2.0 gears:

23" Laser II -- 4800, 47 MPH

21" Laser II -- 5200, 47 MPH
21" Revolution 4 -- 4900, 47 MPH

19" Vensura -- 5500, 45 MPH
19" Alum Black Max -- 5500 45 MPH
19" Laser II -- 5600 47 MPH

posted 02-22-2008 12:53 AM ET (US)            

Now on your 150-HP Outrage, we're back to the 300-RPM difference (slower) with the REVOLUTION4. That's more like the rest of the results.

Glen--that comment was with a big "wink wink"--If PropGods were local to me, they'd be on the speed dial on the office telephone.

posted 02-22-2008 08:53 AM ET (US)            

What was the fuel consumption rate at 5500, if you know?

posted 02-22-2008 09:27 AM ET (US)            

These are interesting stats. I run a Mirage Plus 17 prop on my 225 Opti. Here are my numbers. This is with 3 souls on board, 85 gallons of gas, 10 gallons of water, fishing equipment. Figure the boat comes in at about 5100 lbs.

3500 ..... 27.8 mph 7.9 gph
4000 ..... 33.1 mph 8.8 gph
4250 ..... 34.9 mph 10.5 gph this is the sweeet spot
4500 ..... 36.7 mph 11.7 gph
5000 ..... 41.9 mph 14.9 gph
5725 ..... 46.9 mph 19.6 gph

These are gps numbers using Smart Craft SC 1000.

Not only do I use engine trim but my tabs to level the boat for best fuel economy. How you load your boat makes a big difference.

What engine holes is your Verado mounted on?

posted 02-22-2008 12:12 PM ET (US)            

I am rereading this thread and note that you do not say what propeller is on your Verado 225 power 210 Ventura, but the implication is that it is a 17" Mercury MIRAGEplus. Can you confirm this?

Whoever said the MIRAGEplus is Mercury's worst prop obviously doesn't know what he is talking about. Propellers do not care what brand of outboard they are on, but some boats will make better use of some models of propellers than others. The MIRAGEplus is unusual in that it has far more applications where it is a good fit than most other models of propellers.

This is why the MIRAGEplus has been made for so long, in so many pitches (from 15" to 29", an unequalled range) and continues to be supplied as original equipment by manufacturers who can choose any prop made today, and by high horsepower, high performance powerboaters.

Running the numbers with the data you have provided and assuming the prop in a 15-1/2" x 17" MIRAGEplus it looks like the prop is suffering terrible 23 percent slip at WOT of 5500 RPM and 37 MPH. I have a very hard time believing this.

Yet your cruise numbers make more sense, 3200 RPM at 25 MPH is about 10 percent slip, more in line with what I have come to expect from the MIRAGEplus.

The perplexing thing is that *if* there was something amiss that was causing your prop to slip terribly at WOT it would tend to make it easier for your Verado to achieve higher RPM; it would NOT be a factor in holding it back.

posted 02-22-2008 01:53 PM ET (US)            

That is such a low slip figure that I am skeptical of the data. It could be your tach is off by a few hundred RPM and/or you actually have a 15-3/8" x 18" MIRAGEplus.

posted 02-22-2008 03:22 PM ET (US)         

I think it is *not* Merc's worst prop by a long shot. Those honors go to the aluminum 4-bladed Alpha 4. Stay away from that one. Nor is it one of Mercury's best props, from my experience. On most boat/power applications, you can do better with something else. Personally, I have tried it, and don't like it since if offers practically no lift, doesn't hold all that well, and I have talked with *many* others who also don't like it. I do think it's one of Merc's reliable, all around good performers, a notch above the Vengeance. Mercury says it's best suited for HIGH HORSEPOWER, HEAVY BOATS, as it was actually designed to run fully submerged as a sterndrive prop.

This link is worth reading, for Mercury's own recommendations on applications for each prop line:

http://sites.mercurymarine.com/portal/page?_pageid=126,51007,126_51013& _dad=portal&_schema=PORTAL

Tom Clark says:

(Mirage Plus) "continues to be supplied as original equipment by manufacturers who can choose any prop made today, and by high horsepower, high performance powerboaters."

posted 02-25-2008 09:53 AM ET (US)            

While it is pointless to make blanket statements about what props are good or bad because it all depends on what boat/motor combination one is talking about, I can say that on a twin engine 25 foot Whaler, the MIRAGEplus is a superb performer beating out all the other props I have tested including the Revolution 4, Laser II, Offshore, Enertia, High Five, Black Max, Stiletto Advantage II and the original Mirage.

The large diameter of the MIRAGEplus provides excellent stern lift, something a large diameter propeller are known to do, as well as offering nearly the top speed (which is of little concern to me) of the Laser II and Advantage II.