Lost Rolla Prop

[Megalodon45C]

Well this weekend was a good fishing weekend out of Cypremort Point La, we had a nice limit of red snapper and speckled trout, however on the run home I managed to loose my right hand wheel. I have 30*33 rolla's with a 2inch bore, does anyone know where i can find a new wheel, or who to call? Or what other type of props with what pitch would work. I have a 1990 45C with V92's that are 535hp a piece. Any help would be apppreciated. This part of louisiana is slim pickins when it comes to pleasure craft.
Thanks,
E

[Beckytek]

Sam's has a large inventory of props.

[garyd]

Just curious how and why did you lose it?

You can try ebay as well as some of the surplus yards in Florida.

garyd.

[luckydave215]

I have a set of 33"x32" four blade 2" bore michigan wheels for sale....asking $1,000. (They're in my way, get 'em outta here)
Shipping from the west coast to Louisiana is about $250~$300

[DCMY #92]

Big nut first, or little nut first?

[Megalodon45C]

Guys thanks for the responses, I want to say the last time the props were off and put back on big nut first then little nut, I have a set of michagen wheels and hawbuilt wheels, to me the rollas perform better but maybe i dont have the right pitch on the others. This is the second time that i have lost a rolla prop, lost the left hand wheel around 5 years ago it was a nightmare getting a replacement. The shafts are aquamet 22. i am open for suggestions as to why this may have happened, i dont recall hitting anything.
thanks
E

[mike]

FWIW, you might want to go to boatdiesel.com and look up an article by Tony Athens about how to install props. It's a very good read, he's been in the boat repower business for 20+ yrs, and he claims no fails if you follow his procedure.

[Nonchalant1]

Were the props hand lapped to the shafts? I covered how to do that in a prior thread and it's the best thing to ensure a good fit. A prop is held on the shaft by the tight friction fit between the shaft taper and the prop bore, NOT by the key in the keyway, and NOT by the prop nuts. Both of those are a backup system to the real strength of a good close fit.

A couple hundred hand turns with coarse valve grinding compound, a thorough cleaning and measuring with prussian blue dye is all it takes, and if your problem is a small bend in the end of the shaft or taper area, it will show you that also.

Doug Shuman

[REBrueckner]

If you have lost two props on separate occasions something is wrong..I wonder if maybe you have a metric prop taper and a USA shaft taper...

While the correct procedure is small nut first, then large nut, I've never known nor heard that reversing that causes a lost prop....losing a prop IS unusual...

regardless, it's likely you will lose another prop if you don't find the cause...

[Genesis]

A slightly-out-of-round shaft in the taper will cause this. Repeatedly.

The prop does not properly seat on the taper and as a consequence it will "work" loose. If the nuts are not locked (e.g. with epoxy paste) they will eventually back off and there she goes.

The bad news is that in the process it is at least somewhat likely to place undue stress on the keyway, and may initiate a crack in the shaft there. Eventually this leads to shaft failure as that crack will propagate over time (and cause yet another prop loss along with the shaft breakage)

Perform a VERY CAREFUL inspection of the keyway and shaft to be absolutely certain that a crack has not been initiated before you just replace the prop, and lap the new one on the shaft before installation.

If you are unable to get a clean fit (checking with dye) in 100-150 rotations with lapping compound, the shaft is probably out of round on the taper and needs to come out of the boat and be sent to a machine shop to be checked and trued up.

As noted, this is NOT NORMAL; if you properly lap the wheels and install the wheel properly, with a good fit, the wheel will NOT come off.

In fact, properly fit, the key serves only to hold things in place while you torque the nuts and transfers NONE of the torque during operation; the entirety of the torque is taken up on the morse taper. If the key is taking load it is also putting load into the keyway in a fashion that can lead to shaft failure.