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77 Ski Nautique Prop Strut Driveshaft

Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=51615
Printed Date: November-05-2024 at 1:43am


Topic: 77 Ski Nautique Prop Strut Driveshaft
Posted By: tom_d_77sn
Subject: 77 Ski Nautique Prop Strut Driveshaft
Date Posted: June-12-2024 at 9:23pm
Unfortunately I hit a reef this weekend driving my 77 Ski Nautique in Lac Du Flambeau, WI (Pokegama Lake). The damage appears to be limited to the prop, strut, and drive shaft. I don't know the condition of the transmission at this point. The prop is tight and will not turn. No fiber glass damage. No damage to where the drive shaft enters the hull.

If possible, I want to do the repair myself. I live in Sheboygan, WI and I'm not aware of a shop nearby that would do this. Plus, I rather do it myself to save time and be more capable of fixing stuff in the future. My goal is to get back up and running by the 4th of July (which is probably ambitious). 

Here is my plan so far: (1) Looks like the strut I need would be a SA-154. Need to confirm. (2) I have a friend who says the drive shaft might be able to be straightened as opposed to buying a new one. Need to do more homework. (3) Last time I bought a prop  it was a 13 X 13 X 1 LH. I already know how to change the prop and have a prop puller.

Things I need to figure out:
- How to remove drive shaft
- Where to get the drive shaft straightened if that is a viable solution (or specs for ordering replacement)
- How to re-install drive shaft with new strut
- How to do any necessary calibration or alignment
- Best place to buy strut and prop...I'm okay with used or refurbished parts

Am I crazy for trying to do this myself? Should I punt and take it to a shop? I'm sure if I can find a shop if I drive a few hours. But who knows how long it will sit there until a mechanic can get to it?
 
I've owned the boat since 1999. There is no way I am giving up on her. My family loves the Ski Nautique and its my mission to get her back up and running ASAP to enjoy the rest of the Summer.



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tom



Replies:
Posted By: KENO
Date Posted: June-13-2024 at 9:02am
Originally posted by tom_d_77sn tom_d_77sn wrote:

Should I punt and take it to a shop?


You'll find all the info you need here on CCF so I think you should line up in punt formation, fake the punt and run for a first down Wink

But since you really like the boat, be nice to it and spend the money on a new double taper shaft, a new strut and a new prop

The ARE shaft from Elbert's is one example of a double taper shaft. The original shaft in your boat is 50 inches long and you'd give the info to Elbert's or whoever you might order it through.

It makes life a whole lot easier removing the old shaft and installing the new one. And...... any future shaft removal is a whole lot easier.

The old shaft has an interference fit between the coupler and the shaft and has to be pressed off and if it was straight when you checked it, you'd then get to experience the joy of installing the coupling with an interference fit onto the shaft. That involves a really hot coupling and sliding it onto the shaft in the bilge, hoping you get it right the first time, otherwise you get to press it off again and start over.

That process isn't really any fun at all Wink

So.....you get a double tapered shaft that comes with a matching coupler for the transmission end of the shaft, cut the old shaft right behind the coupler and pull it out from under the boat.

Then you take your strut and replace it with the SA154 that you mentioned (or go through a lot of aggravation, time and money trying to get it straightened by yourself or a prop shop) Sometimes they can be straightened, sometimes they can't 

Then since you have a new shaft and strut, get yourself a new prop. An Acme 540 is a good match for your 77 SN. The old one can be repaired but you'll like the new one from Acme. You can also get a Powertech E40 prop that's basically a copy of the 540 for a fair amount less.

I don't know what you bought a LH prop for in the past, but the one in your picture is a RH prop just like your boat came with from the factory.

The new parts cost you some bucks but you're not paying anybody any labor and having your boat stuck in "boat jail at a shop waiting on someone else to get parts and do it whenever they can get to it.

Prop...........shop around, you'll find a wide range of prices

Shaft .....Elbert's or Discount Inboard Marine. They get them drop shipped from Elbert's.

Strut.....nautiqueparts.com says they have them and use their discount code to get 10% off. The code is PND

Get it all back together and you'll have to do an alignment. Plenty of info on that here on CCF.

Here's a link to a thread on coupler removal that will probably help convince you to get the double tapered shaft

http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25700&PN=1&title=coupler-removal-and-install" rel="nofollow - link

Usually the transmission survives this type of issue with no problems.

PS........I'm not crazy over spending money for new parts when MAYBE the old stuff can be salvaged but in this case it's what I'd do.

Here's your picture rotated so it's easier to see the bend in the strut

https://ibb.co/gFm01dw" rel="nofollow">


Posted By: tom_d_77sn
Date Posted: June-13-2024 at 10:01am
Keno,
Thank you for the sage advice. I am so grateful. I have one question right away. I know my engine is a left hand rotation. I believe you that it is a right hand rotation. How it is that a left hand rotation engine has a right hand rotation prop?

I'll start looking into everything you suggested. Thank you again.


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tom


Posted By: KENO
Date Posted: June-13-2024 at 10:12am
You have a RH prop in the picture and with a Borg Warner 1 to 1 transmission like you have in the boat it has to have a Reverse Rotation (RH) engine driving it.

If you're standing in front of your engine looking back at it and the pulleys rotate to the LEFT, then you have a RH rotation engine.  Clearer terminology would be a Reverse Rotation engine as compared to a Normal Rotation engine like a 351 in a car or truck.

Clear as mud huh?

In the marine industry you look at the engine from the rear and if the pulleys, flywheel rotate to the right, it's a RH rotation engine.

Automotive you look from the front and the terminology difference between auto and marine gets you all screwed up. Wink

Do you still have the tag on the engine with the firing order? if you do, what's it give for the order?




Posted By: KENO
Date Posted: June-13-2024 at 2:56pm
Here's a link that should be helpful that explains "marine" engine rotation with some pictures/diagrams.

http://bpi.ebasicpower.com/faq/rotate.htm" rel="nofollow - link

With your engine and transmission combination, the prop will turn the same direction as the engine when in Forward

You can pretty easily get this done yourself before your 4th of July deadline with help from the forum. Wink


Posted By: tom_d_77sn
Date Posted: November-03-2024 at 11:33am
Hi Keno,

It's been a while since I reached out but wanted to let you know the project was a huge success!

While I didn't quite make the July 4th deadline, we were back on the water by July 19th, saving our summer.

Key takeaways:

1.) Elbert's double taper shaft was a game-changer. Removing the old shaft made the improvement obvious.

2.) Shaft removal was the most challenging part. We used the coupler as a makeshift press, inserting spacers and re-tightening until the shaft was pushed all the way out.

3.) Strut and propeller replacement was straightforward thanks to specs you gave me.

4.) The transmission survived the grounding incident with no damage, as you predicted.

I'm incredibly grateful for your guidance. Your help was invaluable and saved us from a costly repair.

Thanks again,
Tom


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tom


Posted By: KENO
Date Posted: November-03-2024 at 6:00pm
Aw shucks.....you did all the work and now you know you can do these things yourself, plus you saved a bunch on labor charges that you didn't have to pay

Good job Wink



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