HIt something - What to check
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=47830
Printed Date: November-15-2024 at 9:47am
Topic: HIt something - What to check
Posted By: 91NaughtyQ
Subject: HIt something - What to check
Date Posted: July-29-2019 at 12:33am
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Hey guys - I hit something underwater like a log or something. I was going at idle speed heading in to our ramp (no wake zone so maybe 3 mph). Now there is a vibration - What do I need to check to determine if it is the prop or something else. Thanks, Gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Replies:
Posted By: MrMcD
Date Posted: July-29-2019 at 4:30am
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Inspect the prop carefully. Look for exact same contours on each blade, if one has a bend or is shaped differently you found the vibration. If you dont see any shape difference place two fingers on the prop, one inside and one outside and slide them up and down the prop leading and trailing edges. Sometimes you can feel bends that you can't see. With the prop off you can take a magnetic mount dial indicator and check to see if the prop shaft is still straight at the prop mount location. As close as possible to the prop nut location would be best. Eyeball the alignment of your strut to see if it is still square on the hull. A 3 mph hit can certainly do damage but I would think it will be minor. Any bend of even one prop blade can give you trouble. ------------- |
Posted By: KENO
Date Posted: July-29-2019 at 9:42am
I can never seem to find anything magnetic under there, but if I clamp a piece of something magnetic to the strut, then I have something to mount the indicator to  If you have a spare prop, put that on to see what happens to the vibration for comparison. |
Posted By: 8122pbrainard
Date Posted: July-29-2019 at 10:30am
That's why I have one of these:  ------------- /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 < |
KENO wrote:Posted By: 91NaughtyQ
Date Posted: July-29-2019 at 11:01am
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Thanks guys. I will check it out. Gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 91NaughtyQ
Date Posted: July-29-2019 at 11:44am
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Definitely the prop. Appreciate the info fellas. ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: July-29-2019 at 11:52am
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Gary, If you can see the prop took a hit, then defiantly check the prop shaft. With a hit to a prop, it's common for the shaft to bend just aft of the strut. Just as Mark explained (less the magnetic issue! ) the best way is the dial the shat as close to the threaded area as possible. That gives you the best run out reading. It should not exceed .003". ------------- /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: MrMcD
Date Posted: July-29-2019 at 4:47pm
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I guess I am lucky, my trailer has a prop guard that runs directly under the prop shaft. It is easy to mount the magnetic mount for the dial indicator on the prop guard to measure my prop shaft. I realize some trailers do not offer this advantage. Good ideas on the work arounds you guys have come up with. ------------- |
Posted By: KENO
Date Posted: July-29-2019 at 6:33pm
Workaround.................now that's funny |
Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 11:30am
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So i did get a new prop and all the vibrations are gone. Very smooth as it should be. My question is should I still check the shaft? I don't have the dial indicator and would have to purchase one. (I know they are fairly cheap) Not against it if you guys think I still need to check it. Thanks for all the info. Gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: KENO
Date Posted: August-05-2019 at 11:41am
New prop, no vibrations, very smooth I'd say you're OK
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Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 12:01pm
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Thanks! ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: MrMcD
Date Posted: August-05-2019 at 4:06pm
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But, did you lap that prop in? Might need to talk to Pete to stay out of trouble! Glad it is running smooth. ------------- |
Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 4:30pm
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Probably not. Can you explain what "lapping" a prop in means? Gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 4:49pm
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Pete.... Any thoughts if you are following this? ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 4:51pm
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Also I did do a very rudimentary test on the shaft. Took a level and held it about 1/16th from shaft while someone turned prop. Visually looked okay. I know this is far from scientific.... and/or a very accurate diagnosis....... ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: KENO
Date Posted: August-05-2019 at 5:47pm
Usually Google can tell you lots of stuff In this case if you search Google for "correctcraftfan lapping the shaft" or click on the link below, you'll keep yourself busy reading for a while. https://www.google.com/search?q=correctcraftfan+lapping+the+shaft&oq=correctcraftfan+lapping+the+shaft&aqs=chrome..69i57.8167j0j4&sourceid=chrome&ie=UTF-8" rel="nofollow - link To answer a question before you ask it, it's not something that has to be done, you might call it an enhancement to the installation process be sure it's well seated. You can even find some pictures of Pete lapping his shaft |
Posted By: 8122pbrainard
Date Posted: August-05-2019 at 6:27pm
Gary, Ken is correct but it's interesting that Acme actually recommends lapping. I recommend it on any brand of prop. Who's prop did you get? ------------- /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: 91NaughtyQ
Date Posted: August-05-2019 at 6:34pm
OJ legend - Same as original 3 blade 14-16 right hand. ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 6:55pm
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Can't decide if the lapping is a joke or not, but I did not "lap" it in. gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: August-05-2019 at 7:47pm
Gary, What do you think holds the prop onto the shaft? BTW, the prop nut doesn't. It's there to seat the prop on the taper. What do you think transmits 90% of the power from the shaft to the prop? FYI, the key only handles 10%. What do you think holds a drill chuck onto the spindle of a drill press? I'll give you a clue - it's a taper! ------------- /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: 91NaughtyQ
Date Posted: August-05-2019 at 8:16pm
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Ok so I just realized there is a legit video in that thread. I thought you guys were being a bit crazy,(sometimes you can't tell when you guys are bantering with each other - example "Pete lapping is shaft"... - ) but I see it is a real thing. That being understood, do you think I should go back and do this? The prop now has several hours of slalom course runs on it. and it is not vibrating at all. Thoughts? Gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: August-05-2019 at 8:50pm
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Gary, Leave it on as is but, give it a few more hours and make sure it's still tight on 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: KENO
Date Posted: August-05-2019 at 8:55pm
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I'd leave it alone if you're happy with the way the boat is right now. If you decide to do it or want to see the whole process look at the thread titled "Proper prop installation". But beware, there are a lot of pictures of Pete lapping his shaft Here's a link to it http://www.correctcraftfan.com/forum/forum_posts.asp?TID=12866&title=proper-prop-installation" rel="nofollow - link |
Posted By: 91NaughtyQ
Date Posted: August-05-2019 at 8:55pm
Will do thanks. Gary ------------- 1991 Ski Nautique (Previous)1984 Ski Nautique 2001 |