Vari-prop vs. Max-prop

[fstbttms]

Originally Posted by Inthewind

In order to install a Max prop, about 3/4's of an inch of the threads will need to be cut off

Only true in a small percentage of installations.

Originally Posted by Inthewind

under these circumstances, the vessel should probably be hauled out of the water.

Not necessary. Cutting off excess shaft threads underwater is not a particularly difficult task. I have done it more than a few times with zero problems.

[Ex-Calif]

Thanks - My propr must be an older model. No zerk fittings...

[fstbttms]

Originally Posted by Ex-Calif

Thanks - My propr must be an older model. No zerk fittings...

Judging from your pix of the prop, it may be. I have never come across one that couldn't be lubricated with a zerk fitting before.

[Inthewind]

This may be true for you or me or any experienced divers with experience installing Max props but like I said not for a novice. I would venture to say that there are very few divers that have the experience to install a max prop underwater for the first time. Cutting the shaft to fit the classic Max prop like I have is always required, maybe the new Max props are designed so you don't have to. I am only familiar with mine and it is the classic model. Here is a video of Max prop installation instructions.PYI Inc. Max-Prop PSS Shaft Seal Seaview Radar Mounts R&D

Originally Posted by fstbttms

Only true in a small percentage of installations.


Not necessary. Cutting off excess shaft threads underwater is not a particularly difficult task. I have done it more than a few times with zero problems.

[fstbttms]

Originally Posted by Inthewind

Cutting the shaft to fit the classic Max prop like I have is always required, maybe the new Max props are designed so you don't have to.

Sorry, this is simply not true. The prop shaft threads need to be shortened only if they extend too far beyond the Max Prop nut which is not the case in the majority of installations. Model or age is irrelevant.

Here is a quote from the Classic model installation instructions (italics & bold type mine):

One thread can be exposed aft of (the) nut system, if more than that are showing it will be necessary to cut off the excess with a hack saw.

[Inthewind]

In the video titled Nut and Pin installation, he said that on a US built boats, there will be threads exposed and they will have to be cut off. I have a US built boat and my threads had to be cut. So I guess you were right, not all of them have to be cut. Most shafts that I have seen looked like mine before mine was cut. My shaft is now modified to use a fix blade or a Max prop (I know I already said that).

[fstbttms]

Well, you're right in that the video narration does seem to indicate that U.S-built boats will need to have the threads shortened. However, I just called PYI to verify (and spoke with the guy who shot the video) and he told me that this not actually the case. He said that some boats will need shaft modification but most will not, regardless of where they were built.