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Author Topic:   295 Conquest Cruising Speed
jimlawroski posted 08-25-2007 10:12 PM ET (US)   Profile for jimlawroski   Send Email to jimlawroski  
I just purchased a 2003 295 Conquest with twin 225-HP Mercury branded Yamaha four-stroke motors. It seems this boat takes a lot to get on plane and needs about 4,900-RPM to keep on plane and cruise about 27.6-MPH. Is this normal? Is it OK to run these motors continuous at 4,900-RPM. They don't sound like they are screaming. The boat seems to perform best at this RPM. What is the normal cruise speed for this boat?
jimh posted 08-26-2007 10:32 AM ET (US)     Profile for jimh  Send Email to jimh     
I converted your cruising speed to statute miles per hour from nautical miles per hour. Just about all discussion of speeds involving small boats is done using statute miles per hour, and speeds and distances are not kept in nautical miles or nautical miles per hour unless engaged in making long ocean voyages.

Your motors probably lack the low-RPM torque needed to be able to maintain the hull on plane at lower speeds. The Mercury branded Yamaha 225-HP four-stroke has something of a reputation for being a bit weak on horsepower and low-end torque. Yamaha later addressed this problem in their 250-HP model by using variable cam phasing, providing different cam lobes for low-RPM and high-RPM operation so as to enhance the motor's performance.

If you want to improve the acceleration and reduce the speed at which you can maintain plane, try reducing the pitch of the propellers. It would be helpful if you mentioned the current propeller pitch, diameter, brand, and style.

I have been aboard a 305 CONQUEST which was able to maintain plane at speeds as low as 12-MPH. So I suspect that the hull of your 295 CONQUEST--which is not markedly different as far as I know--would be glad to run at that speed if only you had the engine and propeller set-up configured for it.

jimh posted 08-26-2007 10:38 AM ET (US)     Profile for jimh  Send Email to jimh     
I have also removed your identical article which you appended to two other discussions. Conducting this discussion in triplicate serves no useful purpose and really only tends to dilute the information content by spreading it over multiple discussions. Please do not post identical articles to multiple discussions. I am certain you will receive cogent comments here, in this single discussion thread on this topic.
Peter posted 08-27-2007 01:53 PM ET (US)     Profile for Peter  Send Email to Peter     
What propellers are on these motors?
Brian7son posted 08-27-2007 04:23 PM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Jiml,

Man I can name that tune. That's a familiar deal you've got going on with your Conquest.

Here's a quote from my post on this website on 4/17/07:
"I own a 1998 Conquest 285. The boat had had the hull replaced at the factory in November of 2003 under warranty and the prior owner installed 2004 Mercury 225-HP four-stroke motors. The boat also has a 5-kW Westerbeke Generator and an air conditioner. the boat has BIG problems getting on plane when loaded with fuel. The boat has SS Revlolution4 17 props. Once it's up and running, it performs well. I've had it up to 43-MPH with one-quarter of a tank of gas and two passengers. It can cruise at 30-MPH at 4,700-RPM and has great range. However, with a full tank of gas, I actually have to drive in a zig-zag pattern in order for the propellers to "bite" so I can get up on plane."

I tried switching to 3 blades, but went back to the 17 Revolution 4's. I swapped the vent plugs on the props, which you may or may not have. It helped a little, but not much. I tried just about every way to get the boat to plane faster. I had a little success, but nothing to write home about.

I will shoot you an e-mail and you can call me. I dont feel like typing a novel on here. I'll be happy to talk to you about it.

Brian

Brian

Brian7son posted 08-28-2007 10:52 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Jiml,

There are hundreds of folks on here with much more boating knowledge than I have. However, my rig is equipped very similar to yours. After a few years of driving this booat all over the state of Florida and to the Bahamas, I've tried all kinds of different things with it to try and get it to perform (get on plane) better, etc. This is what has worked for me. These tips may not work on other rigs equipped differently, but with mine, after numerous trials, they seem to help. My boat has 2004 twin 225 Yama-Mercs, it's a 98 285 Conquest, LOA 30'10", beam 10'4". Fuel capacity 298 gallons. The 98 Conquest is similar in size to the newer 305.

Try these:
1. When attempting to get on plane. Trib tabs all the way up, bow up position (flush to the hull), motor trimmed all the way down. Hit full throttle, wait about 8-10 seconds, then trim the motor up slightly. I've tried lots of different ways of getting my rig to plane better, that seems to work the best on my particular boat with my engines.

2. When cruising at lower rpm's my Conquest with the twin 4stroke 225 Yama-Mercs does have a tendency to ride bow high. Put your trim tabs all the way down (bow down position). You wont get on plane at lower rpm's but it will drop the bow enough so that you can see oncoming boats, etc.

3. Running your motors at 4700 rpm's will not hurt them. You can run those particular motors at 5,000 rpms all day long. They red line at 6250. However, I will admit, when on long trips with my boat 200-300 miles each way, I like to keep it at 4700. You shouldnt need to be at 4900 rpms to keep on plane. That;s a few hundred rpm's higher than I need to be.

4. These engines dont have very good low-end torque. However, on a positive note, they run long and strong and the range is extremely good.

5. Mine holds 298 gallons. What I have done when going on long trips, is to put around 8/10's of a tank instead of full. That way, you're about 350-400 lbs lighter and you still have 230-240 gallons, plenty of range to go just about anywhere.

Good luck with yours.

handn posted 08-28-2007 04:46 PM ET (US)     Profile for handn  Send Email to handn     
The problem with the 295 Conquest and earlier 28 Conquests are the notched hull.
The hull doesn't run the full length of the boat, it ends a couple of feet short of the stern, the back of the boat continues but there is no hull to support it. It looks like BW made a bigger Conquest but used the hull mold of a smaller boat.
These older Conquests were designed for lighter two stroke engines.
The 305 Conquests have a full length hull and are designed for two Verado's which are heavier than YamaMerc 225's. Because of the hull configuration, they perform adequately with 225 YamaMercs. I have a 305 with this setup.
Brian7son has a lot of good ideas and has overcome the limitations of his boat and engines with creative boat handling.
If it were my boat, I would experiment with moving the engines down. My theory is that the heavy weight of the four stroke engines combines with the notched hull to cause the engines to try to perform in distirbed water. If the propellers were below the turbulence caused by the notched hull, they might get a good bite and put the boat on plane quicker and result in an acceptable cruising speed at a lower rpm.
The fact that the boat rides extremely bow up indicates that the balance and trim needs tuning up.

dr john posted 08-29-2007 11:36 AM ET (US)     Profile for dr john  Send Email to dr john     
Brian, what fuel burn are you capable of? I have a 2002 290 outrage with opti 225's with rev 4 having just raised my engines up and can do 1.2 mph or about 25gph at 4500rpm with 2/3 tank at 27-28 knots with easy seas. That is my best when off shore fishing.
Brian7son posted 08-29-2007 03:10 PM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Dr. john,

I have the 1998 instrument cluster on my rig, dinosaur stuff. Even though I have a new Furuno Chart plotter, I just follow screen to see where I am. I havent charted the exact miles and mpg. I know that my Furuno has the capability to tell me what the distanct is, I just havent checked it. It also cuts through the state (a straight line) when it shows me distance to Miami, instead of calculating going around the hump that is on the eastern coastline of FLA. The next time I go, I will chart plot the course to get the exact distance. I'm usually more concerned about where I am in relation to inlets in case it gets ugly. However, this is my best guess. From my dock, in Merritt Island, FLA to Government cut, in Miami Beach FL, it's about 220 miles.

I can pull from my dock with about 8/10's of a tank, which is roughly 240 gallons. I run at between 4700 and 4800 rpm's which will push me around 30 mph, depending on seas and current. As you stated, this is in calm seas. I can make that run in about 7 hours. When I arrive at Government Cut, in Miami Beach, I have about 1/4 tank left. With my "crude" calculations, I burn about 166 gallons on that 220 mile trip. I have about 74 gallons left in the tank when I arrive. That would translate into about 23.7 gallons per hour and about 1.3 miles per gallon.

When I make this trip, I am on my way to Tavernier Key. I figured that based upon the fact that I still have 1/4 tank when I get to Govt Cut, I could probably make it all the way on 1 tank. However, when cruising offshore (or anywhere), I never take any risks. When I get to Miami, I fill her back up to 8/10's of a tank, grab a rum runner from the Tiki Bar and continue on to Tavernier Key.

Like I said, these figures aren't exact, just my best guess. I'm not an engineer type. However, I have made the trip several times with the same results. Of course, it takes much longer in rough seas.

Brian

jimlawroski posted 08-30-2007 09:14 PM ET (US)     Profile for jimlawroski  Send Email to jimlawroski     
I have 17 inch mirage 3 blade. HOw do I find out the pitch. I have no experience with this. I was reading other discussions which some people said the Rev 4 props made the 295 conquest plane better at Lower RPMS.
Peter posted 08-31-2007 07:49 AM ET (US)     Profile for Peter  Send Email to Peter     
If you have 17 inch Mirages, they are 17 inches in pitch.

The need to turn 4900 RPM to go 27.6 MPH with 17 inch Mirage propellers suggests a 30 percent slip rate which is quite high. It makes me wonder whether the motors are rigged on the transom correctly. That is, are they at the factory specified mounting height and are the motors properly set to the factory specified toe-in/out? Improper toe-in/out and the wrong motor height can severely effect performance on a twin outboard boat, particularly if the rigger got the toe-in/out backwards like they did on my 27 Whaler.

Based on my own experiences with both the Mirage and Rev 4, the Rev 4 propellers will surely do better keeping the boat on plane than Mirages do. The Rev 4 propellers have a tendency to lift the stern which what is needed for a boat like a 295 Conquest.

Before you invest in a new set of propellers, make sure that the motors are rigged right because you should be able to do a bit better, it seems, with what you have.

Brian7son posted 08-31-2007 08:20 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Jim and Peter,

I have the Rev4, 17 pitch props on my 98' 285. The prior owner had a set of extra props on the boat. They were ss 3 blades, I dont know the pitch, but I know that they were "not" Mirage plus. I had swapped them once and checked the performance difference. My boat definitely planes better at lower rpm's with the Rev4's. However, with my 225 4 stroke Yama-Mercs, that's a relative term. I wouldnt say that they perform "great" with the Rev4's, but they perform better with them than the 3 blades that I tried.

On all of the forums that I have inquired on, it has been the general consensus that the Rev4's are the best application for my particular set up. They do give me respectable top end and very good range, just no hole shot to speak of.

Brian

dr john posted 08-31-2007 08:55 AM ET (US)     Profile for dr john  Send Email to dr john     
Thanks for that reply Brian, those #'s aren't bad. I find I get better mpg when cruising 25-30kts rather than at a 20 kt cruise. It's still a mystery to me why you have such a poor hole shot, but is probable related to the 4 strokes. When I used the 17 mirage props, higher top end speed but to stay on plane required a lot higher rpm, which can be tough in rough water.
Brian7son posted 08-31-2007 09:25 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Dr john,

It may or may not be related, but currently I'm having some work done on my boat. The deck is out, so I can see all the stuff that this boat has. The deck hatch is small and in the back, so you cant see much just by opening it up. I knew what was underneath, but when you look at all of it with the deck off, you really see how packed up this particular boat is. It has a 40 gallon fresh water tank, a 5 KW gas generator, the holding tank for the head, a hot water heater and the A/C. I think all of these options, combined with the hull design of the 98 Conquest (which was deigned for lighter 2 stroke motors and mine has 4 strokes), etc. all combine to have an impact on planing.

I had considered dropping my motors down as Handn had mentioned. However, they are already mounted as low as they can be. Im OK with it. It's just a slow planing boat when it is fully loaded with lots of passengers, gear and fuel. I didn't buy it to race with. After all, it's a Whaler with a 10'4" beam, not a Contender with an 8'6" beam. Everything else about it is fine with me. I'm happy with the boat.

Peter posted 08-31-2007 12:07 PM ET (US)     Profile for Peter  Send Email to Peter     
Rev 4s will be the better choice in most cases. That is what I'm running on my antiquated 27 Whaler WD. They give the best all around performance of all of the propellers I've tried.
msc posted 08-31-2007 03:21 PM ET (US)     Profile for msc  Send Email to msc     
I have followed this thread with interest. I have a 2000 Outrage 28 (same hull as the conquest). I, too, have problems with low speed planing and have questioned my dealer on numerous occasions about 4 blade props and they continue to advise me to stay with the 3 blade models. I swapped out the 225 optimax engines for Yamaha F250s. Everything improved except low speed planing. I think I am going to ignore the dealer and try the 4s. For you with Rev 4 props, do you notice any difference when docking? Specifically when in reverse?
handn posted 08-31-2007 05:10 PM ET (US)     Profile for handn  Send Email to handn     
The four blade props give the boat better docking control because of the better bite. However, with the four blade props, the boat goes from forward to reverse or vice versa with a clunk, partucularly noticable with quiet four stroke engines.
Peter posted 08-31-2007 09:25 PM ET (US)     Profile for Peter  Send Email to Peter     
On my boat, docking was greatly improved with the Rev 4s versus any of the three blade props. Also, low speed plane was greatly improved, the boat carries itself through the waves better making the ride more comfortable and the hole shot is much better. With any of the three blade props, I had to go easy on the throttles to launch the boat on plane otherwise the motors would just spin the props into a froth rather than move the boat forward with any reasonable acceleration.
Brian7son posted 09-04-2007 08:39 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
msc,

RE: docking, I have always had my Rev4's on the boat except for my 1 hour prop swap, testing out my 3 blade backups. However, I can tell you that when it comes to docking, my rig does not "twin screw steer" very well. What I mean by that is if I put one motor in fowrward and the other in reverse to try to pivot the rig around while docking, the response and handling of my boat is very poor. I either drive it like a single, or I only put the port or strabord engine in fowrard or reverse for manuvering. Once I got used to that, I can manuver the rig wherever I want without problems.

A friend of mine who used to drive oil tankers for Shell Oil and water taxies in NY, was on my boat one day trying to tell me that it would manuver better by "twin screw steering". I stepped away from the helm and said: "Be my guest. Go ahead and show me how to do that on this boat". After 15 minutes at the helm, he gave up. He said to keep driving it the way that I was.

Brian

PS: msc thanks for the information regarding swapping from the 225's to the 250's. I was considering doing that at some date in the future. However, you saved me some money.

JTC posted 09-06-2007 05:54 PM ET (US)     Profile for JTC  Send Email to JTC     
Brian7son, I've had pretty much the same experience as you trying to "twin screw" steer as well, though I should say that this is my first season with a twin. I've found that spinning the boat on its axis can be quite difficult if there's any real wind or current and that it generally handles much better when driven like a single.

I have a couple of very sharp turns in a tight slip, so I do use the twins in opposite directions to help with the corners, but mostly I drive it like a single.

I think the problem is that the motors are pretty close together and the notched hull may be reducing the effectiveness of the reversed prop. I'm told that it can help to trim the motors up a bit so that the reverse prop wash is directed more under the hull - I may experiment with that the next time I'm out.

I'm sure it's mostly inexperience, but I have found that my 28 Conquest can be a real challenge in the wind. When it's calm, I generally look like a pro! :)

JTC posted 09-06-2007 06:00 PM ET (US)     Profile for JTC  Send Email to JTC     

ps. meant to mention that I have twin 225 Optimax'es and I generally cruise at about 20-25 knots running about 3600 - 4200 RPM or so with 3-bladed Mirages (not sure of the pitch).

Top speed is about 32 knots at 5400 RPM lightly loaded, and I can plane as low as 15 knots at around 3000 RPM. These numbers are all approximate and from general recollection...

With my Opti's I've never had any problem at all getting on plane - it doesn't pop up quite like my 20 Dauntless (with a 1996 Johnson 175 2-stroke), but it basically just goes right on up.

Given all these discussions, when it comes time to repower, I'm going to seriously think about staying with Opti's instead of going to a 4-stroke. I'm told that Verado's are not recommended by BW to repower on this boat...

Brian7son posted 09-07-2007 09:01 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
JTC,

I'm going to run my 225 Yama-Merc's until they run no more. However, if I had the extra coin laying around and was considering a repower, I'd love to see how my/your boat would run with a pair of twin 250 E-tech's. The lighter wieght and the 2 stroke factor is very appealing to me.

msc posted 09-07-2007 09:42 AM ET (US)     Profile for msc  Send Email to msc     
Lest I send the wrong signal my move from 225 Optis to F250 Yamahas has been nothing but positive. Much stronger hole shot, equivalent fuel economy, significantly quieter with better conrtols. No oil fills etc. As for low speed planing I blame that on hull design and the 4 blade props may help that. I do use the engines to spin the boat when docking in most instances. However, there are times that I use only one to dock. I find that when spinning the boat either "goosing" one engine or the other the back will make a significant move in the desired derection.
Brian7son posted 09-07-2007 10:29 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
msc,

I definitely misunderstood your post. When you said: "Everything improved except low speed planing", I was thinking "hole shot". However, now you are saying "much stronger hole shot".

Like I said, I misunderstood. I get in now. You can get on plane quicker, but you still can't stay on plane at low speeds, which we all seem to agree is due to that particular notched hull design. That would seem to explain why Whaler went away from that design in later models.

msc posted 09-07-2007 04:06 PM ET (US)     Profile for msc  Send Email to msc     
That's correct, Brian. Those F250s are great on the 28' Whaler hull. Some people bring up the weight issue on these boating forums but on the 28' hull it's a non-issue.
jimlawroski posted 09-09-2007 06:54 AM ET (US)     Profile for jimlawroski  Send Email to jimlawroski     
Anyone know a good source for the Rev 4 Props and approx what I should pay. Im convinced that I will have better performance in rough seas with these props. I would go to my local BW dealer but I did not buy the boat there and they dont seem to be very helpful. Also, I have no idea how I would know if the motors were mounted properly (toe in,Toe out) Anyone have any suggestions?
Brian7son posted 09-10-2007 04:50 PM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Jim,

Just google "revolution 4 props". you will find tons of dealers that sell them on line. They list for over 500.00 each, but you should be able to buy them for less than that.

Regarding installation and checking the counter rotation set up on your outboards, I have no clue who to use in NJ. I would recommend that you find a good mobile marine mechanic than can come to you and install them. Check with freinds at the marina or call a few local marinas and ask for the name of a good mobile guy.

Keep the old props onboard as a backup set. Mine are mounted underneath the seat storage area in the forward berth. I also keep a pair of backup hub kits with them.

Good luck,

Brian

jimh posted 09-11-2007 03:26 AM ET (US)     Profile for jimh  Send Email to jimh     
My article in the REFERENCE section gives information on rigging details for twin engine installations. See:

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

It is possible to purchase Mercury propellers at a considerable discount from mail-order sources, however it is best to be certain of the propeller you want as often these vendors do not have a return policy, or, if they do, the added shipping costs for sending propellers back and forth can erode most of the discount in a hurry. Propeller testing for counter-rotating twin engines can get to be expensive.

An ideal situation is to find a willing friend who can loan you a set of propellers to test before buying them. Also, some sellers may have a sets of trial propellers available. My local Mercury dealer was kind enough to allow me to spin a few different propellers on trial.

The conventional wisdom on the REVOLUTION4 propeller as compared to the MIRAGEplus is that the REV4's will run about 300-RPM lower than the same pitch MIRAGE.

If I am reading this correctly the boat now has MIRAGEplus 17-inch pitch propellers. If you go to REV4 17-pitch you can expect the engine speed to drop about 300-RPM and possibly more.

There is a rule of thumb that says the engine speed will increase 450-RPM for every 2-inch decrease in pitch and vice versa. If we apply that to the situation, and use a REVOLUTION4 15-inch pitch, you ought to see the engine speed increase about 150-RPM. This may be useful in deciding if you want to try the REV4's in the same pitch or in a lower pitch.

Peter posted 09-11-2007 09:09 AM ET (US)     Profile for Peter  Send Email to Peter     
I saw about a 200 to 300 RPM drop going from 17 inch Mirage Plus to 17 inch Revolution 4s. As far as I know, Mercury still doesn't make a 15 inch counter clockwise rotating Revolution 4 propeller. It's too bad because the Whaler 305 Conquest could surely use those based on the performance report I've seen. Sounds like the 295 Conquest with YamaMerc 225s would benefit from a pair of 15 inch Revolution 4s as well.
Tom W Clark posted 09-11-2007 12:43 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
The Revolution 4 can be ordered for about $450, delivered.

I can affirm that there will be a 200-300 RPM drop when going from a MIRAGEplus to a same pitch Revolution 4.

There is no left hand Revolution 4 in the 15" pitch...unfortunately.

The rule of thumb for large outboards is that there will be, ceteris paribus, a 300-400 RPM inverse change for every two inches of pitch.

JTC posted 09-12-2007 12:32 PM ET (US)     Profile for JTC  Send Email to JTC     

Hmmmm - now I'm seriously considering trying the Revolution 4's as well on my '99 28 Conquest with twin 225 Optis. Better docking control would be highly appealing and lower planing speeds as well. I'm going to see if I can find a local (Boston / Cape Cod) shop who will let me try some props out. Or perhaps I'll splurge this winter along with the inverter I was contemplating.

handn posted 09-12-2007 08:23 PM ET (US)     Profile for handn  Send Email to handn     
My 305 Conquest with YamaMerc 225's goes between 5300 and 5600 rpms with 17P Rev 4's, depending on the load in the boat. Top end is 35 knots. That is in the low to middle of the recomended range. I would get 200-300 more revolutions with the 15p and that would be toward the higher end of the range. I doubt that fuel economy or top speed would change, but the load on the engines would be less.
The real need for 15p Rev 4's is with Verados on big Conquests and Outrages. Verado's rev higher and require a higher reving prop. Mirages are great for bass boats but on blue water with a big boat they are deficient because they won't hold a low speed plane.
It is very puzzling why Mercury doesn't make a counter rotating 15p Revolution 4.
JTC posted 09-13-2007 02:19 PM ET (US)     Profile for JTC  Send Email to JTC     

OK - just bought a pair of Rev 4's from Prop Gods which was recommended to me. Figure the very worst case is that I have some very expensive spare props. Now of course I'm sorry I didn't jump earlier as I might have been able to try them out this weekend!

Will post back about how they compare, and will try to get some decent data on my current performance with the Mirage Plus' on Sunday if Cape Cod Bay isn't too choppy.

Brian7son posted 09-14-2007 08:57 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
JTC,

I think you will like the difference. There was definitely a noticeable difference on my boat. It gets on plane better with the 4 blades vs the 3 blades. Mind you, it's a 98 Conquest, it doesn't jump on plane, but it goets on plane better with the 4 blades.

I saw your note RE an inverter. Dont you have a generator on your boat?

JTC posted 09-14-2007 11:42 AM ET (US)     Profile for JTC  Send Email to JTC     

No generator, unfortunately. Though to be honest I've only had a very few moments when I've wanted one as we mainly just daytrip around Cape Cod Bay. Being able to use the microwave for a few minutes while at anchor in the bay would be handy though.

I've also contemplated getting one of those little Honda portables, but figure that an inverter will be a lot less hassle.

Brian7son posted 09-14-2007 02:18 PM ET (US)     Profile for Brian7son  Send Email to Brian7son     
JTC,

Enjoy the fact that you have 1 less thing that can break and has to be fixed. I like having my generator b/c I will run my A/C when it's 97+ degrees and there is no wind when I'm trolling. You'd be suprised how hot it gets even when you're under the t-top. I can cool down for 5 minutes in the A/C and feel like a new man. Summertime in Florida gets a little toasty. I have not boated up in your area, you may not have the major heat/humidity factor that we have in Florida.
Since I bought my boat almost 2 years ago, I have dropped about $3K on generator repairs and maintainance. Knock on wood, it's working great right now. You know the drill:
B.O.A.T = bust out another thousand

Good luck with the Rev4's, I think you'll like them.

JTC posted 09-14-2007 05:26 PM ET (US)     Profile for JTC  Send Email to JTC     
It's a small consolation for an incredibly short boating season up here (it's very nearly over already!) but yeah, I definitely haven't felt the need to run my air conditioning.

Not 100% sure I'll do the inverter, but looking at some quick numbers it seems like I can gain enough A/C to boil a kettle or heat some stuff in the microwave without too much expense or hassle.

JTC posted 06-03-2008 05:50 PM ET (US)     Profile for JTC  Send Email to JTC     
Just to followup, I had my first couple of trips with the Revolution 4's (17" pitch) replacing the Mirages (also 17"). This is on a 1999 28 Conquest (aka 295) with twin 225HP Optimax motors.

I am really pleased with the Rev 4's. I haven't had a chance to measure my top end speed scientifically (i.e. go back and forth a few times to eliminate current and wind) but anecdotally I'd say my top end is almost exactly the same if not slightly faster at about 33-34 knots. As advertised, the props hold much better than the Mirages and I can trim the motors all the way up without them breaking loose. Same thing when there's a light chop; the motors do not rev up when the boat bounces around.

My top end RPM does seem to have come down slightly which is as expected, and it's at about 5,200. Definitely at the low end of the acceptable range (the Optimax manual says 5000-6000), but as others have pointed out, they do not make a counter-rotating Rev 4 in a 15" pitch, so 17" is the lowest one can go with twins.

I've seen some other folks mention a louder or more noticeable "clunk" when shifting into gear - I haven't noticed anything at all. I would say that there's no difference as compared to the Mirages. On the other hand, I haven't particularly noticed a difference in slow speed maneuvering, but I'm still so lousy at docking and stuff that my attention is generally take up on trying not to hit anything.

I haven't been out in more than 1-2 feet of waves yet, so I can't report how the props perform in rougher conditions, but I expect they will do well and will allow me to stay on plane at lower speeds. So far, I feel that I have a much wider "sweet spot" for cruising. I can easily throttle down to 3600 and tick along on a steady level plane or I can push up into the 4000's and get there faster.

Overall I feel they were a very worthwhile and easy upgrade for my boat, especially for the conditions we encounter around Cape Cod Bay and Nantucket Sound.

Brian7son posted 06-04-2008 04:37 PM ET (US)     Profile for Brian7son  Send Email to Brian7son     
JTC

Good to hear the report. I had figured that the Rev4's were the best application on your rig. Now, you may want to fiddle around with the PVS plugs on your props. They are very cheap. Buy a set of vent plugs with the largest opening and install them on your Rev4's. You will notice a small improvement in planing. The improvement is much more dramatic on smaller boats, but on the big notched hull rig that you and I have, you take what you can get and like it.

Re docking, you need to take a day, cruise out and find a bouy with nothing else around and just manuver for a few hours. At times, I find it can be easier to drive mine as if it's a single engine (i.e. both engines in forward or reverse when manuvering). Our particular model does not spin around well when you try and drive it like a twin screw (put one engine in forward and 1 in reverse). You can certainly do it, but it's sluggish.

I've had mine for 2.5 years and it took me a while to get the docking down. My 22 CC was a lot easier. I'm still not perfect.

Enjoy

Ridge Runner posted 06-05-2008 12:40 PM ET (US)     Profile for Ridge Runner  Send Email to Ridge Runner     
I have to back mine down into a slip, it's still "fun" to watch me do it from the sidelines(I often offer to sell popcorn and soda to the crowd). I agree it's easier to drive it like a single screw then to play with one in foward one in reverse. It seems the notched hull absorbs alot of the reserse thrust. Practice, practice, practice. I have had the same results as you with the Rev4's on my 02 - 295 with Opti 225's. My cruise rmp range was greatly improved, being able to hold plane down to 3,200rpm's.
glen e posted 06-05-2008 01:49 PM ET (US)     Profile for glen e  Send Email to glen e     
a little docking tip: bring the engines up trim wise for 3 secs to where they are straight up and down and not trimmed in - sends the forward and reverse thrust more paralell to the hull....
Brian7son posted 06-06-2008 09:48 AM ET (US)     Profile for Brian7son  Send Email to Brian7son     
Ridgerunner,

Good observation: "It seems the notched hull absorbs alot of the reserse thrust".

I knew that it (the nothced hull) caused the slow planing on the rig, but not until you mentioned this "obvious factor" did it occur to me why the boat doesn't handle well when driving as a twin screw. That makes perfect sense. That is so simple that it eluded me, I couldn't see the forest for the trees.

It handles fine when driving it as a single. Also, when using only the port or starboard engine at times in tight manuvering.

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