Adding strakes to JC Neptoon 21TT, reprop, motor height

[jayw]

We are midway through season #4 with our JC Neptoon 21TT and Suzuki DF150, which I very much like but think there is room the boat for improvement.

We bought it new from a dealer as a leftover year model and had him swap the DF115 for a DF150. The JC Utoons are great and provide a lot of lift but I still think strakes would help us. Had I ordered the boat I would have done the strakes.

A the start of season #1 I replaced the alum prop with a PowerTech OFS18 3 blade. WORLD OF DIFFERENCE. But last yr I let a prop guy talk me into labbing a prop. Not good for a pontoon boat. Wasted 1/2 a season trying to tune it back to where it worked for us, eventually sending it to Rich Junker in FL for a full rework. He got a lot of the bite back, but the blades are now too thin and I feel I am losing power in the chop and fuel economy due to excessive flexing.

So, it's time to reprop. As I do this, I am thinking about adding factory strakes (which would be installed locally by a welder through my JC dealer). Cost is about $2K. Reason to add the strakes is not only to boost the top end, but to get more of the tubes out of the water at all speeds and improve ride in the chop of our very busy lakes (lots of big powerboats).

questions:
1) Anyone run the Enertia ECO yet? Enertia ECO 17P is due out this fall, I think given the 16" diameter the 19P is too much.
2) Strakes: will they improve the ride in the chop as much as I think they will?
2a) Is 4 or 6 strakes the way to go?
2b) How much do they help with loads?
2c) do strakes require a change to the engine height (hole)? according to my JC dealer, JC tells him the height to use for the engine. I wonder how strakes affect the equation.
3) Could I get more top speed from the current prop by raising the motor (I trip way up now but get bow lift from that)

As for props, the Suzuki DFs 150HP+ generally favor a larger diameter prop. They can take up to a 16". I fear the regular Enertia, a popular prop on this forum, is too small a diameter to hold a load well or do well on my boat. Though I've heard Merc props "ast wider" due to materials. I need to find a balance. I am thinking to maybe try (thru Prop Gods):

Mirage Plus 15 1/4" diam
Tempest Plus (or Quicksilver equivalents) 14 5/8" diam
Enertia ECO (after the 17P comes out)

(now sold on Merc props I think based on conversations with Ken @ Prop Gods and Rich Junker at Leading Edge.)

Any help/insight is appreciated.

[Bamaman]

Questions:
1) Anyone run the Enertia ECO yet? Enertia ECO 17P is due out this fall, I think given the 16" diameter the 19P is too much. Your Suzuki is a different animal due to their using a reduction gear in their driveline prior to the gearbox. Suzuki's use a much larger diameter, higher pitch propeller, and you might do best to stick with a Suzuki propeller.
2) Strakes: will they improve the ride in the chop as much as I think they will? If your boat has the wave shield, strakes should make your boat as seaworthy as it can be. Getting the nosecones out of the water is how you get speed and efficiency.
2a) Is 4 or 6 strakes the way to go? Find a tritoon of your brand with strakes, and copy what the factory's done. Strakes are designed by engineers, and tested.
2b) How much do they help with loads? Loads come from having 3 toons.
2c) Do strakes require a change to the engine height (hole)? according to my JC dealer, JC tells him the height to use for the engine. I wonder how strakes affect the equation. Find a tritoon of your brand with strakes, and use the same engine height to start. Speed, rpm's and ventilation in tight corners will tell you if your engine height and propeller are right.
3) Could I get more top speed from the current prop by raising the motor (I trim way up now but get bow lift from that).
Just take it step by step. When you get the prop and engine height balance right, you'll know it.

You might call another dealership carrying your boat brand and see about what they would charge to install factory built strakes. $2,000 seems awfully expensive to me. It might be cheaper to just copy the factory strakes' length, angles, etc. if possible. FYI: It takes a first rate TIG welder/fabricator to do this job as it's easy to blow holes in thin aluminum.

[cwag911]

I might be wrong here but aren't those "U" tubes foam filled? If so you're going to have a rough time welding strakes to them.

[Kilo Bravo]

Subscribed - don't leave us hang'n.

[Bryden24shp]

I am finally going to run the boat tomorrow with this Mystery Prop that Mercury sent me last fall to run. Its supposed to be an ECO, but it is not stamped. It looks like a cross between an Enertia and a Mirage Plus. Its a 17 pitch. Has a hell of a cup to it! I have to get hold of the Merc Rep who gave it to me to find out what the hell he sent me, after I run it.

[jayw]

Questions:
1) Anyone run the Enertia ECO yet? Enertia ECO 17P is due out this fall, I think given the 16" diameter the 19P is too much. Your Suzuki is a different animal due to their using a reduction gear in their driveline prior to the gearbox. Suzuki's use a much larger diameter, higher pitch propeller, and you might do best to stick with a Suzuki propeller.
2) Strakes: will they improve the ride in the chop as much as I think they will? If your boat has the wave shield, strakes should make your boat as seaworthy as it can be. Getting the nosecones out of the water is how you get speed and efficiency.
2a) Is 4 or 6 strakes the way to go? Find a tritoon of your brand with strakes, and copy what the factory's done. Strakes are designed by engineers, and tested.
2b) How much do they help with loads? Loads come from having 3 toons.
2c) Do strakes require a change to the engine height (hole)? according to my JC dealer, JC tells him the height to use for the engine. I wonder how strakes affect the equation. Find a tritoon of your brand with strakes, and use the same engine height to start. Speed, rpm's and ventilation in tight corners will tell you if your engine height and propeller are right.
3) Could I get more top speed from the current prop by raising the motor (I trim way up now but get bow lift from that).
Just take it step by step. When you get the prop and engine height balance right, you'll know it.

You might call another dealership carrying your boat brand and see about what they would charge to install factory built strakes. $2,000 seems awfully expensive to me. It might be cheaper to just copy the factory strakes' length, angles, etc. if possible. FYI: It takes a first rate TIG welder/fabricator to do this job as it's easy to blow holes in thin aluminum.

Thanks (sorry for the long post to follow).

Yes my boat is fully skinned. Back in '09 there were way fewer big motor toons out there, by us anyway. Now they seem common as old pennies. Strakes weren't the norm as they are now - they were an extra. You'd have to be nuts to order a tritoon for anything over 115HP TODAY w/o strakes IMO.

$2K for the strakes did seem a bit high but I would need to negotiate with my dealer still. I could always price elsewhere but then lose the JC warranty. There is another local JC dealer but he is on a ritzy lake and usually much more on stuff. I have no trailer so anything I do has to be transported, either by my marina or by the JC dealer who maintains our boat (he is far off the water). My dealer's plan is to work with JC to be sure they get mounted right, and use another boat as a template. I think if I did it, it would have to be thru JC I would not go with aftermarkets. Cheap is good but best is better. I think they cost about $800 or more as an option when ordering so $2k after the fact - high but not insane. If it meant I was happier, longer, it beats a boat upgrade (though I'd love a Playcraft Daytona - wife not so keen on that one. We'll see, I may be working that way in a few yrs.)

Right now no cavitation, I can trim it up and not lose speed til the rev limiter kicks in if I overtrim. Otherwise RPM is spot on 6100 ish. I do trim up quite a bit but don't HAVE to. Gets the nose up a bit.

Nosecones are out of the water BUT more toon out would improve overall performance. Less drag if I get, say 2/3 of the aluminum out. That's how the straked boats I see ride. Also when it's choppy the cones hit the water, that slows me and wastes gas. Not to mention can make it tougher to control on rough days. Strakes keep more of the toon out, less water off the nosecones, thus better everything.

I do get good lift from these toons, but I have to add more power in the chop to do that. That's every weekend on our chain. The straked boats get on top of the water at lower speeds, and stay there better. That means more speed and better handling and ride. I notice my boat usually rides best with a good (not powerful) headwind. 15 knot wind straight at the bow on a calm lake is when I do the best. THAT tells me strakes would help. The wind is helping me lift just that much more, getting just a bit higher. It adds. 1-2 MPH. In the mid 30s, 1-2 MPH means a lot. But again, it's really the ride in the chop and the handling I am after most.

AFAIK the DF Suzukis above 150 have 2.5:1 ratio so right now I run a PowerTech OFS 18P w/ 15.25" diam. prop but could go to 16". Likely I think the 16" will slow me down top end though I may get slightly better mid range performance from what I hear. Before I did that I'd just go 4 blade and maybe save more gas, or go to the Enertia ECO in the fall (if they get their act together on the 17P).

I think Suzuki props are made either by Yamaha or one of the Chinese brands (Solas?), depending. Not impressed by the SOlas brand on stainless. Aluminum, fine. I've run 'em before on other boats. I think I would stick with Merc and find one that works, based on talking to Ken. Or back to PowerTech but they are not the fastest props on the mkt. They are usually mid range and always behind Merc in every test I see.

Looks like JC may only do 4 strakes, no outers. Overall I still like the boat very much, I like the JC brand (save for a few nuances and quirks/shortcuts) but the build quality is great. Interior is great quality. Very stylish. Not an old man's boat by any means.

[jayw]

I might be wrong here but aren't those "U" tubes foam filled? If so you're going to have a rough time welding strakes to them.

Dont' think these are, the welder has had the caps off a couple times to fix damage caused by my marina's huge forklifts (when they had clumsy and obtuse drivers). Also my center toon has a 53 gal (yes 53 gal) fuel tank built in.

I will double check though, but in any case the guy slated to do it is an excellent welder. Just have to make sure it is HIM not any of his guys do it. He's a great welder (not so much luck on the prop side from him but that's OK).

[jayw]

BTW we have in and out service so the boat never stays in the water, comes out every time we use it so no crud to deal with. Makes the strakes install much easier.

[jayw]

I am finally going to run the boat tomorrow with this Mystery Prop that Mercury sent me last fall to run. Its supposed to be an ECO, but it is not stamped. It looks like a cross between an Enertia and a Mirage Plus. Its a 17 pitch. Has a hell of a cup to it! I have to get hold of the Merc Rep who gave it to me to find out what the hell he sent me, after I run it.

I am dying to hear about this one. Merc told me fall on the 17P. Isn't that too small a pitch for you?

[Bryden24shp]

I am dying to hear about this one. Merc told me fall on the 17P. Isn't that too small a pitch for you?

I don't know, with this drastic cup, it may work! Gonna spin it in a few hours, hopefully... Sky is lookin perty gloomy right now. But its not supposed to rain until late. I never was a fair weather boater, though. Thats why we bought the S-Series! I'll let you know how it runs. I'll grab the camera and pop a pic of it, too. Boat hasn't been wet since last September. Hope it still floats!!!

[Bryden24shp]

Here it is..
The boat ran 5900 RPM's at 48.6 gps mph. Trimmed just alittle over 1/2 up. The Cavitation plate was about 3" above the waters surface at WOT. You could hear the props ears slapping into the water. From the 19 Mirage plus, I gained about 600 RPMs. From a 17 Enertia, I lost about 300 RPM's. (cupping?) But slip came in at an amazing 5%!!! The fuel economy was great. At 5900 RPM's. 2.9 @ 3500 RPM's 3.6 and at 2600 RPM's 6.2! This is with a 310 horse, 625 pound Verado on a 3200 pound boat! I have never seen that on my SmartCrafts!
I'm thinking dropping the motor down 1 set of holes will help even more with the prop slip at WOT. I called Merc and left a message for them to call me tomorrow. My Rep has left the company (probably for giving out props for free) his email is kaput, We need to find out what this prop is! Because the slip factor is amazing!
As soon as I get more info, I'll let you know.
Beautiful day for a boat ride. Out for about 4 hours went through 1/4 tank of gas.
For the first time out, on stale gas, the boat ran flawlessly. Only hitch of the day, the wife told me she wants a new Manitou, with the same dual windshields...
Greg, (Manitou) if you read this.... The boss has spoken! Lets give her what she wants!!! Give me twin 300's on it, too! I'll help ya design it!!!

[jayw]

Here it is..
The boat ran 5900 RPM's at 48.6 gps mph. Trimmed just alittle over 1/2 up. The Cavitation plate was about 3" above the waters surface at WOT. You could hear the props ears slapping into the water. From the 19 Mirage plus, I gained about 600 RPMs. From a 17 Enertia, I lost about 300 RPM's. (cupping?) But slip came in at an amazing 5%!!! The fuel economy was great. At 5900 RPM's. 2.9 @ 3500 RPM's 3.6 and at 2600 RPM's 6.2! This is with a 310 horse, 625 pound Verado on a 3200 pound boat! I have never seen that on my SmartCrafts!
I'm thinking dropping the motor down 1 set of holes will help even more with the prop slip at WOT. I called Merc and left a message for them to call me tomorrow. My Rep has left the company (probably for giving out props for free) his email is kaput, We need to find out what this prop is! Because the slip factor is amazing!
As soon as I get more info, I'll let you know.
Beautiful day for a boat ride. Out for about 4 hours went through 1/4 tank of gas.
For the first time out, on stale gas, the boat ran flawlessly. Only hitch of the day, the wife told me she wants a new Manitou, with the same dual windshields...
Greg, (Manitou) if you read this.... The boss has spoken! Lets give her what she wants!!! Give me twin 300's on it, too! I'll help ya design it!!!

Wow. Your report makes me think, wait for the ECO. It's 16" diameter, right? How to explain the increase over the Mirage I cannot say as you kept pitch but went up 1/2" diameter. As for the regular Enertia, well you're stepping up almost 1.5" in diameter so no surprise to me.

So you think it's the best prop you've ever run on your boat?

Regular Enertia is no good for me b/c of its small diameter. I would be happy in calm water, lightly loaded, that's it. Unfortunately that won't be enough. I need a good all-around prop with tons of lift (bow) and good top end (PowerTech mostly fits the bill, now I am looking for the Merc prop that COMPLETELY fits the bill!). Tip cup really helps my boat lift the nosecones higher.

Mirage dilemma for me:
15.25" 19P may be too much prop (?)
15.5" 17P may be too little
-of course I am basing that off experience with PowerTech so maybe totally off (only run PowerTech SS props on this boat so far)

So for this prop can you tell me/us:
How was midrange power?
How was hole shot?
It's still X7 alloy, right?

If you want to get rid of that prop let me know! I would buy it. I don't have to wait til fall. I'm sure the regular Suzuki Flo Torq hub would work on it.

[jayw]

the wife told me she wants a new Manitou, with the same dual windshields...
Greg, (Manitou) if you read this.... The boss has spoken! Lets give her what she wants!!! Give me twin 300's on it, too! I'll help ya design it!!!

Manitou makes some nice boats. Our marina sells Premier, that Premier SS is really nice. I'd be happy with the Playcraft Daytona but I don't think I want to ever go back to 2 stroke (ProSX). Oh well no new boats for me any time soon, we still think of this one as "new".

[Bryden24shp]

So for this prop can you tell me/us:
How was midrange power? GOOD
How was hole shot? GOOD
It's still X7 alloy, right? SUPPOSEDLY, looks the same as my Enertia.

I contacted Mercury to find out more on this prop since my contact is no longer with them. No markings at all on it.

Its a keeper, sorry. I'll be keeping it!

[jayw]

That labbed Powertech OFS3 split a blade half way through over the weekend. My fuel economy had gotten SO BAD with that prop, I knew something was wrong. Total prop failure.

Luckily I had already ordered a Mirage Plus from Ken at Prop Gods. Due in Thursday. He recommended it extremely highly for my setup. Told me he can't recommend any prop more given what I have. he also told me the ECO won't run as good on my Suzuki as it runs on the Optimax. Optimax realizes extra advantage for the diameter and prop characteristics due to its huge gearcase per Ken.

For now I do what Ken says, he is the "prop god". I know the regular Enertia would disappoint. The Tempest wil be best top end, that's it.

My only concern is that bow lift. If this works out and I want more bow lift I send it to Rich in the fall for tip cupping. I had the aluminum Suzuki 14.25x21 backup prop on, it runskinda flat. If the Mirage does better than the AL Suzuki I may just be happy with it. I can trim a bit more if I get the bite I expect. The Suzuki lets loose if I trim up and turn the wheel.