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Author Topic:   320 Outrage performance update
TightlinesPE posted 09-02-2005 11:14 PM ET (US)   Profile for TightlinesPE   Send Email to TightlinesPE  
320 owners - chances are - if you have Verados, your motors are mounted too low.

I just had mine raised to the top hole (BW didn't do it right) and I should be going higher, but BW screwed it up.

I am still turning the same wheels (17P Rev 4's) and my top speed has gone from 46 to 50. Fuel burn has gone down 4 gph.

The boat also runs much better with more stern lift and more ventilation for the props at the higher height. Not even completely trimmed out I got 6000-6100 RPM a motor.

Check your motor heights. This boat is possibly a 55 mph boat with Optimax XS mounted at the correct height, propped right, and no bottom paint or obstructions. a 275 Verado/320 Outrage owner claims 52 w/o bottom paint. I don't know if his motors are at the correct height but manufacturers are mounting the Verados too low - and in this case, mine too.

They are still too low.

Boat is quicker than I thought it was and she really likes to run. She rides better going 50 in 1-2 than 28 mph.

I would be probably to 53 mph and maybe more if I moved them up more and turned 19 Mirage props...I'm disappointed I can't.

whalerdude posted 09-03-2005 12:35 AM ET (US)     Profile for whalerdude  Send Email to whalerdude     
You have my dream whaler!

Are you happy with the ride and handling of the boat.
How about the quality?
Do you have active deck susp?

Perry posted 09-03-2005 01:30 AM ET (US)     Profile for Perry  Send Email to Perry     
What size Verado's does the boat have, 250's? 275's? What hole were the motors mounted from factory? Are you saying that the motors are now mounted all the way up on the 4th set of holes?
prm1177 posted 09-03-2005 01:29 PM ET (US)     Profile for prm1177  Send Email to prm1177     
Do you remember where your anti-ventillation plates are now in relation to the bottom of the boat? Are the outer edges of the plates above or below the hull?
Peter posted 09-03-2005 08:43 PM ET (US)     Profile for Peter  Send Email to Peter     
How's the water pressure with the motors lifted up? If I were you, I'd contact Whaler to find out why they mount the motors lower from the factory. Remember, the whole argument for the tieing arrangement is that Whaler is supposed to be an "expert" in the rigging of its boats and making sure that there aren't any problems. Maybe they are just being conservative, maybe not.

Just thinking aloud here but one reason I can think of for mounting the motors lower is that you've got pressurized straight six engines that have their top most cylinder most likely farther away from the water pump than any other motors of comparible HP. I would be concerned that by raising the motor and lowering the water pressure from the pump, the top cylinder might not be getting enough water for cooling purposes if the pressure drops off too much. I think its worth a call to Whaler to discuss. In any event, keep an eye on the water pressure and cylinder temp.


sideshow posted 09-03-2005 10:28 PM ET (US)     Profile for sideshow  Send Email to sideshow     
Same applies to the 305 & 255 Conquest models fitted with Verado's.
TightlinesPE posted 09-05-2005 07:42 PM ET (US)     Profile for TightlinesPE  Send Email to TightlinesPE     
Hey guys,

The outside edge of my cavitation plates are still under water while on plane with level trim.

The cavitation plates are approximately 2.5-3'' above the bottom. They were about an inch and a half before they were raised. The boat also has about 24'' of set back on the transom.

My buddy who raised them for me owns a huge dealership of Wellcraft and Fountain boats. Both often come with Verados and he has told me that 80 percent of manufacturers of boat he's seen have the motors too low. He says they can still come up more without a problem.

Additionally, the Rev 4's I'm running have a ton of bite. I was hauling arse back home to avoid a thunderstorm (about 45 mph) and went across a sportfish's wake...all 5 ft. of it (without tabs because they were broken)and launched the hull but the motors still somehow never broke loose with the units buried and the hull aired.

I also was able to catch up to a 26 Island Runner on his way out (we were both running on the pins) and never broke loose at all even with getting a little air off a couple waves.

I still have not had ANY issues with blowing out and the REV 4's just keeping biting regardless.

I am running 250 Verados. I have not really had a ton of water rough enough to see how she handles but without tabs she will take a 2 ft. chop, chew it up, and spit it right back out. As time goes on here, it will gradually get rougher as winter comes so I will report to the ride. She is very dry. She will pound in the tiny bit of rougher water experience I've had but I didn't slow down...I feel she rides better going faster since she likes to ride on top.

The boat handles great. She loves to run. Making sharp turns on plane is never a problem. I do not have ADS (20K!). It's just one more thing to break. The motors were mounted 2 holes below the top hole from the factory, so we raised them two to the top hole. They are mounted all the way up.

If I had low water pressure to any of the cylinders, I would know by a loud and obnoxious beep complimetry of the Smartcraft system and the digital System View offered with the Verados. I get alarms even when I air out the pitot/trans for the system. I will check the water pressure next time, but if I was roasting the top cylinder, my computer would probably let me know. I will keep an eye on the water pressure next time. Thanks for bringing that up.

prm1177 posted 09-06-2005 09:56 AM ET (US)     Profile for prm1177  Send Email to prm1177     
The location of the cavitation plates sound about right. The inboard side of the props are close to breaking the surface at this point. I think you're being fooled a bit by the tenacious bite of the Rev 4 props. I wouldn't raise the motors any higher. Sit back, enjoy your ride, and resist the temptation to fiddle further. Besides, 50 mph+ in a boat this size... Sheesh!
TightlinesPE posted 09-06-2005 03:31 PM ET (US)     Profile for TightlinesPE  Send Email to TightlinesPE     
and weight/power ratio is pretty good!

It is not possible to raise them anymore so they are staying where they are.

Thanks for the input!

sideshow posted 09-07-2005 04:39 AM ET (US)     Profile for sideshow  Send Email to sideshow     
Tightlines PE

Can you please give me a few tips on prop selection from your experience. I have a 305 Conquest with 250 Verado's. They are currently fitted with 15inch Mirage props. My engines are about to be raised 2 notches higher as they are definately too low and not reaching anywhere near 6000rpm. Do you have any prop suggestions. I would like to be able to improve fuel economy if possible, I usually cruise at around 27knots offshore. It is usually too rough to travel over 30 knots, so top speed is not so relevent.

thomasfxlt posted 09-07-2005 07:56 AM ET (US)     Profile for thomasfxlt  Send Email to thomasfxlt     

If you are still running the factory setup (as I am), you should be able to rev the Verados WOT and fully trimmed to around 6150. I had a discussion with the marine engineer at BW about the motor height and they insist that their testing shows the factory setting to optimal. I agree, however, that their conservatism relative to unknown variables may contribute to a less than high performance position of the motors. BW's primary concern expressed in our discussion was that of cavitation in rough seas. I'd like to hear some experience of others that have change the motor position on a 305 and used it agressively offshore before I have the dealer move the motors up. I also think that if I were to do this, the benefit of the 4 blade, 15p prop will be essential. As of right now, the left hand prop is not available.

Peter posted 09-07-2005 08:24 AM ET (US)     Profile for Peter  Send Email to Peter     
I agree with Whaler's concerns based on my own experience with both Mirage and Rev 4 props on my 27 Whaler WD. The Mirages performed poorly in rough seas where keeping the boat on a slower plane is critical. The Mirages were not up to that task at all, cavitating frequently causing the boat to lose its momentum which in turn made for a poor quality ride.

I switched from 17P Mirages to 17P Revolution 4s late last year and have used the Rev 4s the entire season this year. The ride of my 27 Whaler WD has improved significantly. I lost about 2 MPH of top speed as a result of the switch. Fuel economy is just ever so slightly less overall with the Rev 4s (they are actually better at the slow plane speed because they don't lose their grip) but the significant improvement in the ride makes it well worth it. The boat can be held on a slow speed plane with no difficulty now.

I think the problem with the Mirages is that they didn't have enough blade surface area to carry the load properly. They were fine on smooth water above 28 MPH but not so good when slower speeds are desirable, such as when traversing 2 to 3 footers.

I expect that the Conquest 305, being a heavy and wide boat would have the same problems with ride and cavitation in a rough sea state. I expect that it would certainly benefit from 4 blade propellers. Hopefully, Mercury will come out with a left hand version of the 15P Rev 4. I think a pair of 15P Rev 4s would probably be ideal for the 305 Conquest/Verado or Optimax combination.

sideshow posted 09-07-2005 08:42 AM ET (US)     Profile for sideshow  Send Email to sideshow     

My 305 at WOT revs to approximately 5800rpm.

JWhaler123 posted 09-07-2005 12:56 PM ET (US)     Profile for JWhaler123  Send Email to JWhaler123     
Just to add a little bit of 320 info...
i have a friend with a 320 with Twin 275 Verados and it runs about 50mph from new, with antifouling and fuel so run in maybe a bit more. That is at factory height settings.

The quickest 320 by far though that another friend owns is rigged with Twin Yamaha 300 HPDI's which are lighter and more powerful, now that 320 really flys. It ran easily over 56mph with fuel and 4 people on board. Sounds fantastic too.

Verado's are great to use and are very quiet, good allrounders and super smooth but if you want to go quickly in a 320 the YAmie 300's are superb.

Happy Whalering

TightlinesPE posted 09-07-2005 07:35 PM ET (US)     Profile for TightlinesPE  Send Email to TightlinesPE     
If you want problems, the Yammy 300's are the way to go.

Those motors have been blowing powerheads as long as they've been out along with some 250's.

Stay away from Yam 300'

If you are an owner with a lucky set, all the better, enjoy your motors.


With the weight and overall design of your boat, it is not a speed demon and as you said, you don't need it to be either. The 305 is a lot of boat.

When you get your motors raised, check your WOT RPM and your fuel burn. Your fuel burn will likely be better and RPM's will go up some at WOT. If you find you are breaking out and running over 6000 RPMs, you may want to try out a pair of 17p Rev 4's....they will certainly give you a ton of bite, may take your fuel efficiency down a tad, but you will have great control at the dock and good bite offshore. I think your situation may just be okay if you are running 15p Mirage 3 blades even with the motors being raised. I don't know when counter rotating 15 p 4 bladers will be available...but hopefully soon.

Check your stats now...if you are getting your good RPM's at WOT, that's great. If you are getting better fuel efficiency, all the better. Run her in some rough stuff and following seas and see if the motors blow out at all. If not, I don't see the need for 4 bladers or lowering the motors. I think 17P is a little big for a big boat like that to swing so check your stats and report back here if you can...

In my opinion, if you are not blowing out with 15p Mirages and you are getting better numbers across the board as far as fuel efficiency and RPM's at WOT...the 15p Mirages are probably as best as you can do...because 17p rev 4's, I think, will suck your fuel efficiency back down a little bit along with speed and RPMs. Check it out and let us know what you find...

I also would not worry about frying your cylinders furthest away from the water pump. The Verado has a low-water pickup.

sideshow posted 09-09-2005 06:13 PM ET (US)     Profile for sideshow  Send Email to sideshow     
Thanks you for your feedback.

I shall lift the engines and stay with the 15inch Mirages for the time being, then see how it goes from there.

handn posted 09-09-2005 07:59 PM ET (US)     Profile for handn  Send Email to handn     
I agree with Peter. Revolution 4s even with 17p are the way to go.
They are optimal with my 305 Conquest and YamaMerc 225's, I doubt that my top speed would increase even with a 15p were they available in Revolution 4's as my rpms with the 17p's are 5500, right in the middle of the recomended range.
I had a Mirage 15, 15p with my 23 Conquest and single 225 Optimax. The 15 Mirage broke loose and cavitated in heavy seas at any speed below 22 knots. I had better luck with a Mirage 16, 13p. More surface area with the 16 inch prop helped lower speed performance and the fuel economy and top speed were the same even though the engine ran 200-300 rpms higher with the lower pitched prop.
In real world conditions 4 blade props are the only way to go with a big heavy boat like a 305 Conquest or a 320 Outrage. Until Merc comes out with a Revolution 4 in 15p, the 17p Revolution 4 is the best choice.
TightlinesPE posted 09-09-2005 08:35 PM ET (US)     Profile for TightlinesPE  Send Email to TightlinesPE     

You make a good point. However, the YamaMerc and the Verado are two completely different motors. The Verado should spin at least 6000 in my opinion...this is a good indicator that the boat is not overpropped, the motors are not buried, and that the motors are under such a tough load to only be able to spin under 6000. The rev limiter on the Verado is set around the mid 6000's, I believe. So, let's say you can turn 6500 max...which not a lot of boats can unless they are underpropped or they have the perfect situation.

Even though your YamaMercs can turn in the middle of their range, the Verados turn in the 6000's at WOT...or they should at least. That is why I think the 15p Mirage is a good prop for a heavy boat that will turn the RPM's the Verados will run at. This proves they are not under too much stress to push the load.

However, if Sideshow starts having cavitation issues, I would recommend trying out a set of 17p Rev 4's and keep the motors right where they are. Chances are, he will lose some RPM (not drastic), but he will have plenty of bite for the height they are at. If he is not having cavitation issues, then why fix something that is not a problem? The 305 is undoubtedly heavier (I can only assume) than the 320...however, my 320 with the motors at the height they are at, have not much of a problem turning 6100ish RPMs at WOT. I'm interested to see how the Mirages will run with them jacked up...he may have to get some Rev 4 17p, but when he reports, we will see!

sideshow posted 09-20-2005 08:53 AM ET (US)     Profile for sideshow  Send Email to sideshow     
Raised the Verado's 2 holes higher to the maximum height hole. After initial testing results are:

Top Speed: Increased from 37knots to 42knots.

Maximum RPM: Increased to 6150rpm. Can't remember what is was before, think it was around 5600 - 5800rpm.

Holeshot improved noticably.

I still have the original 15inch Mirage props. Conditions today where quite good with only a small chop. Will see how the setup goes in offshore conditions on the weekend with the raised engines. Haven't done any fuel consumption comparisons yet however I would assume an improvement at cruising speeds.

Will experiment with different props in the next few weeks. My initial conclusions are that the engines are too low from the factory for the type of boating I do. In fact I can't really imagine why anybody would want them lower from my initial results.

sideshow posted 09-23-2005 06:21 PM ET (US)     Profile for sideshow  Send Email to sideshow     
Went 40miles offshore today, good test with the new engine positioning. Had no cavitation issues at all. Definately the performance of the boat has improved. Fuel economy has also improved. Think I might stick with the Mirage 15's for the time being.
TightlinesPE posted 09-24-2005 11:55 PM ET (US)     Profile for TightlinesPE  Send Email to TightlinesPE     
Great news! 42 knots is excellent for that boat!!!

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