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Author Topic:   2001 CONQUEST 28 Re-power
Kris Boutilier posted 03-10-2014 08:28 AM ET (US)   Profile for Kris Boutilier   Send Email to Kris Boutilier  
Hello all. I have a 2001 Boston Whaler CONQUEST 28 with twin Yamaha 250 EFI Ox66 two-stroke-power-cycle engines. I am re-powering with twin 2005 Mercury Verado 250. The boat is 30'8" LOA, 10'4" beam, and 8,400 pound dry weight without engines.

Looking for some info on what props to run, the brand, diameter, and pitch. Looking for a combination of top speed and fuel efficiency.

Also any other info on this re-power.

Kris

Tom W Clark posted 03-10-2014 10:11 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Try a pair of 14-5/8" x 17" Revolution4 or 14-1/4" x 18" Enertia propellers.

If cruise speed fuel economy is your primary goal, try a pair of 15-1/2" x 17" MIRAGEplus propellers, or see if you can order a set of the new Enertia ECOs, though only the 19" are on the market yet and 19" will be too much pitch.

The Revolution4 will yield about 7-percent calculated propeller slip, the Enertias will yield about 10-percent slip.

The Enertias will also have a slightly higher top speed.

jimh posted 03-10-2014 12:58 PM ET (US)     Profile for jimh  Send Email to jimh     
Kris--do you have data about performance with the present engines?
Kris Boutilier posted 03-10-2014 04:18 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Yes I have some data.

-top speed is about 41 miles/hour at 5400 RPM

-best cruise is 1.1 mpg at around 30 miles per hour.

- does not plane or stay on plane at under 24 miles per hour.

Propeller: 14" three blade S/S, counter rotating

Looking for top end speed, fuel efficiency, and lower planning speed for choppy water.

I wanna make sure I get the exact prop I need as 2 enertia's will run me about $1600 + dollars.

Peter posted 03-10-2014 04:31 PM ET (US)     Profile for Peter  Send Email to Peter     
Doesn't the Conquest 28 have the stepped keel at the transom? If so, how is it going to perform with the extra 300 lbs of weight the Verados will put on the transom?

I think I would be leaning toward putting Rev 4s on to get some stern lift. I don't know whether the Enertias are stern lifting.

Kris Boutilier posted 03-10-2014 05:52 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
I have spoke to boston whaler about that and they said it won't be a problem with that boat.

Also, I have done some reading on the internet and there are people with 4 stroke yamahas and Hondas that work good on same hull. Also some came from the factory with 4 stroke yamamercs.

I just wanna ensure I get the right prop for this application.

Kris Boutilier posted 03-10-2014 05:59 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Just read the post of the guy who repowered his 295 (same boat as mine) with 4.2 litre 250 yamahas. They are a little lighter than the verados though. He pops right up on plane.

He is running

17" Revolution 4 props

If would prefer the enertias for the top end though.

Kris Boutilier posted 03-10-2014 06:02 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Here is the info on the twin yamahas on the 295 conquest repower

WOT:
47mph
5,700 RPM
1 mpg

BEST CRUISE:
28mph
3,800 RPM
1.5 mpg


SLOW PLANE
14mph
2,800 RPM
1.1 mpg

Flat and Calm conditions, 3/4 fuel (230 gallons). 17" Revolution 4 props.

The RPMS above 38 were also pretty efficient: 1.4mpg up to around 4200-4300 and then dropping down from there. So the boat will run through the upper range of speed without burning much extra fuel.

I measured speed both on the GPS and from the speed sensor on the motor itself and they correlated well. I was running across the breeze (which was pretty much nonexistent anyways) and tried it both directions so I feel that these numbers are pretty accurate!

Needless to say I'm very pleased with the results of the repower. I am especially happy that the boat appears to be propped just about right... I know that ideally I'd get a couple hundred more RPM at WOT, but they don't do the Revolution 4 in 15" counter rotating, so I'd have to move to an entirely different prop which I don't want to do.

Tom W Clark posted 03-10-2014 06:29 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
quote:
...they don't do the Revolution 4 in 15" counter rotating...

As of last summer, they do.

14-5/8" x 15" Left Hand Revolution 4 part # 48-8M0064449

Tom W Clark posted 03-10-2014 06:30 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
quote:
...2 enertia's will run me about $1600 + dollars.

Even in Canada they should not cost that much.

Kris Boutilier posted 03-10-2014 06:53 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
I got quoted 795 each plus have to pay 15 percent sales tax. Mercury dealer ran my details through prop calculator and came up with 17 enertias
Tom W Clark posted 03-10-2014 06:55 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
You should be able to get them for $1,200 Canadian, delivered with hub kits.

Know anybody in the US who can mail them to you?

Kris Boutilier posted 03-10-2014 09:08 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
No, don't really know anyone to do that. I will get my merc dealer to see if the mercury rep has any demo props. Worth a try.

Tom any reason you think I should go with 18" pitch on the enertia's instead of 17".

Tom W Clark posted 03-10-2014 09:11 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Yes, I think your boat is potentially a 51 MPH boat not a 48 MPH boat. I could be wrong.
Tom W Clark posted 03-10-2014 09:17 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
$795 each plus 15 percent sales tax is $1,828.50 Canadian!

I'll send you a pair for $1,500 Canadian, but I think you could do even better.

Kris Boutilier posted 03-10-2014 09:53 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Thanks Tom, I will check around. I have been reading through different forums and found that most people were putting the Rev4 17" props on conquest 295's & 28's. Were the enertia's not around several years back.

The biggest complaint is low speed planning. Will I be able to low speed plane with the enertia's or should I really think about the Rev4's. Seen some people complaining about low speed planing with the 225 yamamercs.

I do believe that the verados have better low end torque than most other 4 strokes and some 2 strokes which should help with low speed planning. Correct?

What prop would you put on if you were me. Looking for the best all around prop. top end speed, fuel economy, hole shot and low speed planing.

jimh posted 03-11-2014 12:56 AM ET (US)     Profile for jimh  Send Email to jimh     
A long time ago, and I don't remember the exact date [It was April 24, 2004--jimh], Wil Rogers of Boston Whaler took me on a test drive of the then new 305 CONQUEST. It had a pair of the big six-cylinder Verado engines. He proudly demonstrated that by tucking-in the engines all the way he could keep the CONQUEST on plane at a ridiculously low speed, around (or perhaps even less than) 15-MPH, as I remember.

I don't remember what propellers were on the boat. It was a good demonstration of the low-RPM power in the Verado. They seemed to be able to crank out enough horsepower at a relatively low engine speed to keep the boat on plane.

I think you will find that a lot of modern, computer controlled engines can do that, and do it a lot better than older outboards could.

Yes, I know it was a different hull, and maybe the 28 CONQUEST won't do that. But I thought it was worth mentioning when you mentioned lower planing speed in choppy water. That is an important trait to have in a boat if you are out in big water. We run our boat like that all the time, and we love being able to set the engine speed and have it run right there. Modern engines will do that.

Peter posted 03-11-2014 05:51 AM ET (US)     Profile for Peter  Send Email to Peter     
"The biggest complaint is low speed planning. Will I be able to low speed plane with the enertia's or should I really think about the Rev4's. Seen some people complaining about low speed planing with the 225 yamamercs."

The Yamahamercs don't have the torque to hold the boat on plane. The Verados do. It then becomes a propeller grip problem.

With the Rev 4s, I was able to hold my Whaler 27 WD on plane at a speed as low as 15 MPH. I could not do that with any 3 blade propeller, they would simply break loose. Also, when putting the boat on plane I had to ease the throttles forward with the three blade propellers otherwise they would break loose. Switching to the Rev 4s solved both of those problems.

If you want the ability to hold down a low speed plane, which may be more difficult with the stepped keel at the stern, then I think you have the best chance of doing that with the Rev 4s.

Tom W Clark posted 03-11-2014 10:24 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
I note that Boston Whaler chooses NOT to use the Revolution 4 on either the contemporary 285 Conquest or the much heavier 315 Conquest when fitted with twin Verado 250s.

They use the Enertia.

Interesting.

Kris Boutilier posted 03-11-2014 02:36 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Thanks for the replies guys.

Do you think that because the verados have very high torque that the verados would be able to keep the boat on plane at lower speeds using a 3 blade propeller compared to other older 2 strokes and older four strokes such as the F225.

Is the enertia's geometry different then other 3 blade propellers that it will help with low speed planning like a 4 blade prop.

Kris Boutilier posted 03-11-2014 02:42 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
One more thing, basically what I am getting at is if I knew that planing would not be a problem at around 17 miles per hour for choppy water I would definitely choose the enertia as I should get better top speed and fuel economy.

Also sometimes I like cruising at lower speeds.

kglinz posted 03-11-2014 04:56 PM ET (US)     Profile for kglinz  Send Email to kglinz     
I own a 28 Conquest.. I think that if a motor will turn a prop at a given RPM it doesn't matter if it's a "strong" Verado or "weak" Yamaha. I run 17" Rev 4s. I have tried 17" Mirages and a set of 15" Turbos. I fall off plane at about 20 or 22 kts with Mirages depending on fuel load of course. With Rev 4s I can stay on plane down to 16 to 18kts. In rouge water I run motors trimmed down all the way and tabs down. Mirages will get you about .2 MPG better fuel mileage. My motors aren't as heavy as yours, but I have 5 heavy AGM batteries just ahead of the transom and a generator, so there may not be much difference in weight.

Kemp Lindsey

Kris Boutilier posted 03-11-2014 05:05 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Thanks for the reply. What engines are you running.

So you are saying that torque does not affect low speed planing.

If torque does effect low speed planing the verado should perform very well with a 3 blade prop

See attached graph I found. Verado low RPM torque is much higher than the other outboards.


http://www.ybw.com/forums/showthread.php?385610-Outboard-power-delivery

kglinz posted 03-11-2014 07:12 PM ET (US)     Profile for kglinz  Send Email to kglinz     
The amount of torque may control the amount of time it takes to reach a given RPM, but once it's at a given rpm it doesn't matter if you are turning it with a 200 HP engine or a 300 HP engine. Now if your talking about climbing steep swells, then your torque comes in to play if you're trying to run at slow planning speed. Your RPM (speed) will drop going "up hill" so you need enough power to maintain planning speed. I don't really understand all this stuff about stern lift and bow lift. I know I've got props worth about $2,000 I don't use. I run a pair of F225 Yamaha engine.
Kris Boutilier posted 03-13-2014 06:54 PM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
With the weight of the four strokes are your scuppers still above waterline?
jimh posted 03-13-2014 07:36 PM ET (US)     Profile for jimh  Send Email to jimh     
Modern outboard engines with plenty of reserve power will tend to hold the engine speed you set them at under varying loads. They run like they were a big diesel engine. At least that is the performance I experience with my modern 225-HP engine. If I set the throttle to a nice slow planing speed, my modern engine will run at that speed. It will not drop 500-RPM the minute it has a bit of a swell to climb, and it won't race to 1,000-RPM higher when it comes over the swell. I had an older 225-HP engine that lacked modern computer control of the fuel and throttle. It would not hold the boat on plane at a low speed. The engine speed would drop off and the boat would fall off plane.

The test ride I experienced on the 305 CONQUEST with the Verado engines had the same sort of performance as I have now with my modern engine. You could set the throttle of the Verado engines for a nice slow planing speed, and they would hold the boat there. They apparently had enough power being produced at that low engine speed they could handle the load that was resulting. This is not intrinsic in all engines of any horsepower and design. You get this from modern engines that have a wide power band. You do not get this from older engines with peaky power ranges.

This characteristic is important if you, like Kris Boutillier, who started this discussion, are "looking for...lower planning speed for choppy water."

As I mentioned earlier, but will now elaborate, we run our boat at low planing speeds in choppy water all the time. We do this with great enjoyment because we previously could not do this with our old engine. With our old engine we had to run the boat much faster to stay on plane, and in rough seas the ride that resulted was very uncomfortable. To be able to keep the boat on plane at a much lower speed in choppy water is a very desirable characteristic in a boat. The choice of engine will affect this. I think that having modern engines like the Verado will probably be as asset in getting this sort of characteristic in Kris's boat. Note that Kris has said his boat presently "does not plane or stay on plane at under 24 miles per hour."

Another asset of these modern engines is relief from having to constantly work the throttle in these low speed planing modes. I find I can set the throttle and forget about it. I concentrate on steering the boat. When your engine does not behave like that, you have to spend a lot of effort continually adjusting the throttles. If you have twin engines, you have to adjust two throttles--twice as much work.

jimh posted 03-13-2014 07:41 PM ET (US)     Profile for jimh  Send Email to jimh     
Also, modern engines have electronic throttle controls. With twin modern engines you get a bonus: automatic throttle control of both engines with one lever. This will make handling the boat at low planing speeds in choppy seas even easier for Kris. The Verado is a modern engine and has modern features. It should be a nice improvement for his boat.
dave_maggio posted 03-19-2014 08:10 AM ET (US)     Profile for dave_maggio  Send Email to dave_maggio     
I have the 295 with the Honda 225's, no problems with the scuppers, have four blade props, top out at a little over 40mph and am able to get the low speed plane that you want even with the generator option and 4 big batteries in the back. Interesting to note that my setup is not all that sensitive to extra weight in the fuel tank, not sure why.

I know you said you are buying Verados, but, just looking at the specs I keep thinking that the 300 Yamahas would be awesome on this boat, a bit lighter in the stern and all the HP and torque you could ever want.

Kris Boutilier posted 03-28-2014 09:54 AM ET (US)     Profile for Kris Boutilier  Send Email to Kris Boutilier     
Thanks for the reply, I am sure 300 yamahas would be awesome but price is a big thing with this repower. The repower is only going to cost 6000 Canadian as I sold my present motors and controls for 8300 Canadian. The Verados are come with gauges and controls.

I have ordered mercury enertia 17" props for the repower.

Kris

dave_maggio posted 03-30-2014 10:39 AM ET (US)     Profile for dave_maggio  Send Email to dave_maggio     
Kris, sounds like you are spot on given the pricing. The Verados are super nice motors! Please do share the results with us after you are complete. While I love the Hondas and hope that they run reliably for a good long time, I have always wondered what an extra 150hp would do for this hull.
JTC posted 04-25-2014 06:17 PM ET (US)     Profile for JTC  Send Email to JTC     
Love to hear how the repower went! Please post some performance figures and pictures when you have them!

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