Acme 543 Prop

[js9467]

I bought an 87 Tristar this year and have done a BUNCH to it. The boat had a pretty bad vibration when getting up on plane. I had it serviced and the mechanic aligned the shaft but it still didn't rectify the issue. I decided Thursday to bite the bullet and buy a new prop. After quite a bit of research here on TT and a conversation with Richard at Discount Inboard Marine, I decided to go with the Acme 543. I just got off the lake and am AMAZED! It's like a new boat!! Smooth as silk and SO much more "umph".

My question is this... I have never replaced a prop. I basically pulled the old prop off, and installed the new one the same way as the old. There were some washers of different thicknesses I'm assuming for the purpose of positioning the cotter pin properly. I tightened the nut as hard as I could by hand and reinstalled the cotter pin. I'm asking because I'm nervous that my $400 investment will end up at the bottom of the lake. Any advice??


Sent from my iPad using Tapatalk

[memphis23]

If the pin is in you will not lose the prop. I am not sure of the lbs needed to meet factory specs but what you have said above sounds like a good install as long as the cotter pin is in, I also have an Acme and have had similar results from SKIDIM

[_fng_]

I have the same prop and love it as well. Use a new nylon lock nut and check it every time off the water for the first few times to make sure it doesn't shift/loosen. Others will suggest having a seal by grinding the prop shaft down with some compound but I talked with my local MC shop and they said it wasn't necessary so if you're overly concerned you could seal it with the fit (blue compound) or just trust the tightened lock nut. The cotter pin is a backup plan I'm hoping never needs to be tested as I'm not sure how much it would stop if the prop got loose.

[js9467]

Thanks! I noticed that some of the nylon was worn/gone in the lock nut. I'll find, purchase, and install a new one hopefully before the weekend.


Sent from my iPad using Tapatalk

[js9467]

Ok... Another question. Te nut that's on the boat seems to be a castle nut with nylon. Skidim has one or the other but not both which leads me to believe that it would be beneficial to keep the one that I have.

http://www.skidim.com/searchprods.as...number=1&val=0




Sent from my iPad using Tapatalk

[_fng_]

I would go with the brass nylock nut instead of reusing the old one. Or call around the hardware stores to see if you can find a replacement oem piece.

[EJ OJPROP]

You should use the brass nylock. There should not be any washers either. The washers are in place to insure the pin will go through the castle nut.

[js9467]

If I were to pull the washers off, there would be a bunch of space between the end of the nut and the cotter pin. Is that ok??

[EJ OJPROP]

There will be less space when you use a nylock nut. Like I said the only reason to use the washers is to allow the pin to hit the castle nut in the right place. Not a fan of the castle nut, if pin fails the nut is coming off followed by the prop at some point.

[snobinge]

If I remember correctly last time I checked the torq spec for the nyloc nut is 32lbs ish.