G23 Prop Fell Off .....

[scottb7]

The new X Star may be worth a look? Not to invite backlash, just a thought.

If I was shopping for a new boat I would look at the new Supra SL before jumping into anything. And for a lower price point I would like at new Axis A24.

[swc5150]

Just sold my Axis today, and will start the process of buying or ordering a G23. This thread kinda makes me wonder/scared of buying a G. Wouldn’t be happy to have this happening after paying that kind of money.


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The new X Star may be worth a look? Not to invite backlash, just a thought.

[nohlan_4]

Ha! ha! Have you tried this yet? How far do you think a trolling motor is going to push a 6000 pound boat on those batteries? I think someone stuck that trolling motor in there as a joke.

Batteries will last forever just run the motor while operating the trolling motor......charge with the power of the alternator.

[Nickleej]

Just sold my Axis today, and will start the process of buying or ordering a G23. This thread kinda makes me wonder/scared of buying a G. Wouldn’t be happy to have this happening after paying that kind of money.


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[scottb7]

Scott here is my tow vessel should I have an emergency such as shearing off my prop

Nice. Or this.

[Beach-TJ]

Looking through the pictures of failures i don't see evidence of failure due to torsional loads. The shafts have no twist in them.
From building jeeps i have seen what a torsional force does to a shaft, and it is obvious after failure.
I wonder what grade steel they are using, what forging process ( hot, warm, cold ) and what heat treating process.
So many factors, each affecting torsional strength, shearing strength, and corrosion resistance.
Hopefully they get it straight.

[GMLIII]

Fits nicely...

Scott here is my tow vessel should I have an emergency such as shearing off my prop

[scottb7]

I could be wrong. But I thought the taper allows for the load to be shared around the whole shaft.?

[Bevostein]

I wonder if Nautique should move to splined shafts vs a keyway.

From this article - http://gearsolutions.com/features/inside-splines/

The benefits of using a splined shaft in the place of a keyed shaft are many. The spline connection provides an equally distributed load along the sides of the teeth. This shared load provides a longer fatigue life verses a keyway drive. Different types of spline tooth forms allow for stronger drives, the ability to slide, transfer of rotational concentricity, allowance for misalignment and, in the case of helical spline drives, the transfer of axial and rotary motion at the same time.

[Wake.BC]

I’ve heard of one Tige failure and it was on a older boar, no Malibu failures... so yeah there must be something different here.

You can’t go by saying it’s the angle of the boat when surfing, they’re all the same. They all run 17” props on the 2:1. Prop angle too steep on Nautique?


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[Wake.BC]

I’ve heard of one Tige failure and it was on a older boar, no Malibu failures... so yeah there must be something different here.

You can’t go by saying it’s the angle of the boat when surfing, they’re all the same. They all run 17” props on the 2:1. Prop angle too steep on Nautique?


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[Evening Shade]

I know it will never happen, but it would be cool to see a stress test on prop shafts from Nautique, MC, Bu, and Tige to see how much torque each can withstand before they fail.

[Wayward]

1) To learn more about forging check out this website: https://www.steelavailable.com/en/wh...steel-forging/ Furthermore, I don't know what you mean when you say "

shafts on my G had an obvious machined surface, whereas on an MC, it isn’t." as if this somehow indicates it is

forged. All shafts are machined at the prop end. Mastercraft uses a Splined shaft. By definition it is machined.

2) I don't know what measurements you have seen to state that the G is the most bow down boat ever built. All surf boats have a plate at the stern of the boat that can be used to rise the bow to create greater pressure at the stern resulting in a steeper wave with more push. This is the setting most frequently used to SURF. Skim boarders might prefer to lower the bow by lowering the plate to push the bow down. This reduces the pressure at the stern resulting in a longer and less steep wave. Every surf boat can raise or lower the bow based upon riding preference. Granted the G does have a lower gunwale in the bow. This is to improve driver visibility when in a bow high configuration. The down side of this design is that one can take on water over the bow when the ballast is full if you hit a large wave. Perhaps better visibility is attributed with a more bow down boat? But that is perception, not the angle of the hull to the water. Finally, the bow high attitude is ONE factor contributing to the failure. This factor combined with the 2:1 transmission, 17" prop, and fully loaded ballast at surf speeds ALL contribute to increase shaft loading. Many boats can have larger props, but not larger props with all of the other characteristics in a large enough sample size to experience the shaft shearing that has occurred. I believe we are talking about tens of shafts sheared in several thousand boats.

3). Stock prop on what? If you look at https://www.ozpropellers.com.au/mast...at-propellers/ The only Mastercrafts with 2:1 Gear ratios are the X20, X23. Both of these boats use the 16.0 or 16.5" props. Many boats use larger propellers than 17". But they don't have a 2:1 transmission, and push heavy surf loads too. I'm not defending this design, just identifying the factors that cause the failure.

1- AFAIK, and by looking at the splines themselves, the shaft splines are rolled......

2- No measurements, just easy observations. While surfing, the G series boats run with a much lower bow attitude than any other competitive wakeboat. In most regards, this is one of the best aspects of the G while surfing. It is a well known attribute, and owners love that they can see better while driving. I don't understand what you mean about having lower gunwales in the bow. As far as i can remember, my Gs had fairly uniform gunwale heights from the back to the front. The thing I remember most, is how much bow rise the boat didn't have while surfing, and I liked that. Have you ever driven a Malibu MXZ while surfing, and without a 1000lb bow bag in it? That would give you an idea of a boat that rides bow high while surfing. And they run a 2:1 with a 17" prop....... and there are plenty of those out there for a good sample group.

3-New XStar (with any motor), and the X26 with a 7.4l, run a 18" prop with a 2:1 gearbox.

Have a chat with the service manager at a few different dealers....... the failure rate is more like 50% which makes sense, when at least half of the G owners on PN have had failures, and several have had multiple failures. I know members on here that have had failures, that didn't bother posting about it....

either way, I'm not trying to bash anything. They all have their own stupid issues, and their own engineering fails. This has gotten old, though. This problem is now 5 years old, and still happening at a high occurance rate. Something needs to be done IMO.

[scottb7]

"Granted the G does have a lower gunwale in the bow. This is to improve driver visibility when in a bow high configuration. The down side of this design is that one can take on water over the bow when the ballast is full if you hit a large wave. Perhaps better visibility is attributed with a more bow down boat? But that is perception, not the angle of the hull to the water."

Yeah, NO...From the wakeboard perspective what is a fact, and I love about the G, is that it runs the least amount of bow rise - and yes I mean angle of the hull to the water - then most boats in general (and all nautiques in particular) to produce a comparable wake. And the gunwale is really high on the G, and is pretty darn difficult - thankfully - to take water over the bow. (Ease at which you can take water over the bow is the only thing I can fault my 2008 210. Absolutely everything else about that boat was unbelievable for its dry weight and ballasted weight.)

I would get an axis a22 or a24 in a heartbeat if my g didn't create the same wake with lower bowrise. But my wife would run into someone not being able to see...

[scottb7]

Ha! ha! Have you tried this yet? How far do you think a trolling motor is going to push a 6000 pound boat on those batteries? I think someone stuck that trolling motor in there as a joke.

Yeah, I tried it. Worked great. Not saying you get much speed. Trolling motors use very little power so can go a long time...Not saying you gonna get there fast. But better then having to have 3 guys lined up behind the platform kicking, I figured.

I think in actual use it would depend on wind, etc. how fast you would actually move but it works fine...very cheap insurance...

At first it bothered me to carry it, but after people had shafts break second time on same boat, I figured - since I had it - I better leave it in.

The issue I have is that we are first on the lake in March April and last off in October November. There is NO ONE that would be able to come save us on my baby sized lake.