Vibration
Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=49853
Printed Date: March-04-2025 at 4:14am
Topic: Vibration
Posted By: beretta5spd
Subject: Vibration
Date Posted: May-30-2021 at 12:23pm
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Hi guys, Of course now that I've just got Perfect Pass installed and running great.... I've noticed that I have a vibration at all times when the boat is moving. Here are some of the details / things I've checked. Boat: 1995 Sport Nautique. Original TBI swapped to Quick Fuel M600 carb. Original protec ignition. 1. I did hit something last year right at the end of the ski season that caused me to have to use my spare prop and get my original reworked. I have asked a friend to borrow his prop which doesn't vibrate on his boat to test this week. Hopefully that's all the problem is. In the spirit of worst case scenario and I've knocked everything out of wack.... here are the rest of the details: 2. The shaft turns very smooth in the cutlass bearing. 3. The shaft in the cutlass bearing has some (minimal) movement up/down if I'm pushing HARD. 4. The cutlass bearing at the propellor side of the strut appears quite worn on the bottom. There is a gap at the top and worn on the bottom (see photo. photo is 90* out of orientation. Left is up, right is down) 5. Using a dial indicator.... the shaft midway between through hull and strut is spot on. 6. Using a dial indicator.... the shaft right after the strut is spot on. 7. Using a dial indicator.... the shaft right before the castle nut threads is close (.003 TOTAL variance.) What order of operations would you complete attempting to smooth out the vibration? Thanks in advance.  ------------- 1996,1997 Sport Nautique 1986,1992 Ski Nautique - Sold 1995 Sport Nautique - Current |
Replies:
Posted By: ultrarunner
Date Posted: May-30-2021 at 12:32pm
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My first guess would be you spare prop is causing the Vib. You'll know in short order when you swap with your friends prop. With that said, it also appears you're due for a cutlass replacement, so I'd do that regardless.
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Posted By: 8122pbrainard
Date Posted: May-30-2021 at 12:43pm
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I agree that the spare prop is suspected but, the .003" at the tail end of the prop shaft isn't the greatest. If a prop change doesn't do it, then it's the shaft. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Jonny Quest
Date Posted: May-30-2021 at 12:51pm
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Before striking underwater object = no vibration. After striking underwater object = vibration. I’ll bet you a dozen of Tim Hortons’ finest that the prop or shaft (or both) is bent. I believe .003 TIR is max tolerance on the shaft. Likely spot to bend is aft of the strut. Did you have a CNC prop when you struck the object? In my experience, a CNC prop that has been hit and repaired seldom performs like new. Today, I look at a CNC prop as “disposable”. I realize that others have had better experiences with repaired CNC props, but my luck has been poor. Based on your description of how the shaft sits in the strut bearing, indicates that a strut bearing replacement and shaft alignment are also in your future. JQ
------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: TRBenj
Date Posted: May-30-2021 at 6:55pm
| Disagree… though repair quality can vary greatly. Have had one prop that was repaired more than once that was still capable of 60+ and smooth as silk the last time the engine could push it that fast. Others (usually bought used and repaired by an unknown shop) looked fine but were junk. YMMV |
Posted By: Jonny Quest
Date Posted: May-30-2021 at 7:38pm
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Tim: I wish I had your luck. Maybe the prop shop I used was the problem, as the props that I had repaired never seemed to perform like new. The came back from the shop looking good, but top speed was down and the "smoothness" seemed to be gone. As such, my repaired props go to Ebay or the “spare” pile. JQ ------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
Posted By: MrMcD
Date Posted: May-31-2021 at 3:41am
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I too believe you should look at a new cutlass and shaft alignment. Start with it perfect and you won't ever regret it. If your prop shaft is only .003 out of true a machine shop should be able to dial it straight again easily but ask price in advance, labor may be the same as cost of a new shaft. I had an ACME 224 on our 95 Ski Nautique, it had minor injury that was repaired at a local prop shop and it was perfect, I loved that prop. Unfortunately it was injured a second time and I had it straightened again by the same shop. The prop was not the same, it is smooth and has good power but I lost 3 MPH top end. I bought a new Acme 422 to replace it. I like the 422 a lot but preferred the 224 in its original form on this boat. My 95 has the 310 HP GT 40 and we run at sea level or 1,500 ft elevation most times. ------------- |
Posted By: beretta5spd
Date Posted: May-31-2021 at 9:23am
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Thank you everyone for the comments. JQ original prop was OJ 3 blade (can't remember specs). My spare prop was also OJ 3 blade that someone tried bashing with a hammer on the strut side to remove *facepalm.* I'll keep you all updated along the way. ------------- 1996,1997 Sport Nautique 1986,1992 Ski Nautique - Sold 1995 Sport Nautique - Current |
Posted By: beretta5spd
Date Posted: June-01-2021 at 11:34pm
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Good news! 95%+ of the vibration was eliminated by switching props. I contacted a friend 400+ miles away who owns some towboat dealerships and he says his crew can tune / balance the props I have. Rob next time you come to Canada “Timmy’s” is on me :) ------------- 1996,1997 Sport Nautique 1986,1992 Ski Nautique - Sold 1995 Sport Nautique - Current |
Posted By: Jonny Quest
Date Posted: June-02-2021 at 12:29am
Timmy's and a pull behind the Nautique!
------------- Current 2003 Ski Nautique 206 Limited Previous 2001 Ski Nautique Open Bow 1994 Ski Nautique Open Bow Aqua skiing, ergo sum |
beretta5spd wrote:Posted By: beretta5spd
Date Posted: June-02-2021 at 5:47pm
Slalom, Trick or Jump you pick ;) ------------- 1996,1997 Sport Nautique 1986,1992 Ski Nautique - Sold 1995 Sport Nautique - Current |