Prop is slightly loose-96' Ski Nautique
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=39090
Printed Date: April-28-2024 at 10:09pm
Topic: Prop is slightly loose-96' Ski Nautique
Posted By: 2tall
Subject: Prop is slightly loose-96' Ski Nautique
Date Posted: June-24-2016 at 6:01pm
|
At a slower speed at the back of the boat I heard a sort of loose click sound like maybe the cotter pins on the swim platform were loose and hitting just slightly against the metal brackets that hold the swim platform on...so I got under there after trailering it and found that the prop is just slightly loose. I can move it just barely back and forth and it seems to be causing a loose rattle noise. It still has the cotter pin on the castle nut, but the castle nut is not super tight. I can't tighten the castle nut any more because then the cotter pin would not fit in the slot (the whole purpose of the castle nut). So can I add a spacer just before the castle nut? I only need something super thin maybe less than 1 mm Or maybe a different castle nut with more slots? ..any ideas? ------------- 2Tall - 1996 Ski Nautique GT-40 |
Replies:
Posted By: 8122pbrainard
Date Posted: June-24-2016 at 6:11pm
|
The prop wasn't installed properly. It needs to be lapped to the shaft. The prop nut is there to seat the prop to the shaft and then a safety as you found out. ------------- /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: June-24-2016 at 6:18pm
|
Do a search on this forum for lapping the prop to your shaft. It only takes about a half hour to do but is very important to a safe installation. As far as locating the cotter Pin you could add a washer under the nut but the lapping process is what holds your prop to the shaft so don't skip that part. |
Posted By: 8122pbrainard
Date Posted: June-24-2016 at 6:24pm
|
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=12866&KW=proper+prop&PID=145077&title=proper-prop-installation#145077" rel="nofollow - Proper prop installation ------------- /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: 8122pbrainard
Date Posted: June-24-2016 at 6:26pm
Not needed. Seat the prop with the nut after lapping and then back the nut off to the closest slot for the cotter. ------------- /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 < |
MrMcD wrote:Posted By: 2tall
Date Posted: June-24-2016 at 6:48pm
|
So it seems to me the prop was maybe seated almost correctly at some point, but came loose and the person before me backed off the castle nut just as you suggested to fit the cotter key, but the real problem was the propeller was never lapped properly or maybe not tightened enough with the nut when they installed it? Am I getting the picture? ------------- 2Tall - 1996 Ski Nautique GT-40 |
Posted By: 8122pbrainard
Date Posted: June-24-2016 at 8:19pm
|
JD, With a lapped taper, it doesn't take much force to seat two components together. If the prop/shaft was lapped and then the two seated, you can remove the nut!!! I've seen it where the prop nut is gone, likely for some time and the prop is still there. Prop pullers are made for a reason!  ------------- /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: DrCC
Date Posted: June-24-2016 at 8:40pm
| It could also be a result of too much lapping. Removing material from the prop bore allowing the prop to move further up the shaft taper. |
Posted By: 8122pbrainard
Date Posted: June-24-2016 at 9:00pm
Al, Please note that there is no mention of running out of threads but rather the nut can't be tightened anymore so the cotter pin can be inserted in the hole. I have experienced props where the prop shop has re reamed a bad bore on a prop and then yes, a washer is needed behind the nut but that's due to no threads left and not from multiple lapping. ------------- /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: June-24-2016 at 9:15pm
| Torque specs for a 1" shaft propeller nut are listed from 30-50 foot lbs. I would feel better leaving the nut tight as the manufacturer recommends, although I fully recognize the value of proper seating of the prop to the shaft. |
Posted By: peter1234
Date Posted: June-24-2016 at 9:28pm
|
when i used the napa valve lapping compound on my skylark i was amazed at how much material seemed to come off the prop. it took as said above about 30 minutes to remove an awful lot of play. ------------- former skylark owner now a formula but I cant let this place go |
Posted By: 8122pbrainard
Date Posted: June-24-2016 at 9:37pm
Mark, I agree that there's certainly a "piece of mind" with a tight prop nut but am also glad you understand the taper principle. ------------- /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: SNobsessed
Date Posted: June-25-2016 at 12:12am
Isn't it possible for the key to bind & prevent the tapers from mating? ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: MrMcD
Date Posted: June-25-2016 at 5:23am
|
I watched a You Tube video that showed how to check the Prop fit with and without the key installed. Basically install the prop with no key and mark where it seats on the shaft. Next install the prop with the key installed and it should seat at exactly the same spot if not the key or keyway needs to be file fitted so it allows the prop to seat properly. It helped when I installed mine last year. Until this forum taught me proper prop installation I had never lapped one in in 30 years of boat ownership. Once learned the process makes perfect sense. |
Posted By: eric lavine
Date Posted: June-25-2016 at 11:53am
|
Pete, really? 30000 posts??????? ------------- "the things you own will start to own you" |
Posted By: gun-driver
Date Posted: June-25-2016 at 12:25pm
|
Holy crap WELCOME BACK ERIC 
|
Posted By: 8122pbrainard
Date Posted: June-25-2016 at 5:58pm
Eric,  Where have you been?? Fill us in. ------------- /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: 2tall
Date Posted: June-28-2016 at 4:32pm
|
So I went and bought the Prussian Blue and the grease mix grinding compound. I got the propeller off (easily, it was already loose) and rubbed a thin layer of the Prussion Blue around the shaft as suggested. It looked perfectly smooth. There apparently were not any high or low spots. Is that possible? I did this about 5 times with varying degrees of Blue on the shaft just to be sure and each time I see the same result. The Prussian Blue is perfectly distributed on the shaft and there appear to be no high/low points. So I cleaned off the Blue, put the key and the propeller back on, and tightened the castle nut. Then I backed off the nut just barely and pulled on the prop (by hand) and it is on there nice and tight I could not move it. So does this mean the shaft was in excellent shape and I don;t really need to do anything more? That is what it seems like to me. I inspected the length of the entire shaft and it looks brand new all the way to the motor. No scratches, no nicks or marks and it shines bright. it must be new? So how did the propeller come loose? Maybe it wasn't tight enough previously? ------------- 2Tall - 1996 Ski Nautique GT-40 |
Posted By: Hollywood
Date Posted: June-28-2016 at 4:34pm
http://www.correctcraftfan.com/forum/forum_posts.asp?TID=38425&PN=1&title=whens-it-gonna-happen" rel="nofollow - http://www.correctcraftfan.com/forum/forum_posts.asp?TID=38425&PN=1&title=whens-it-gonna-happen |
Posted By: KENO
Date Posted: June-28-2016 at 5:01pm
The tranny man is still number 3 on the all time hit list behind TRB and ahead of Hollywood in spite of being away for years I think he might have passed Pete by now if he stuck around |
Posted By: backfoot100
Date Posted: June-28-2016 at 5:02pm
If the key wasn't properly seated between the shaft and prop keyways the prop itself will never seat onto the taper. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: 63 Skier
Date Posted: June-28-2016 at 8:14pm
Eric, nice to see you stop by. Please let us know what you are up to, you've been missed! ------------- '63 American Skier - '98 Sport Nautique |