Bravo III props - what is the difficulty for removal?

[Presentation]

Jeremy,

Thank you. That is what I will do.

 

[BluzCruz]

This is easy if you have the correct tools. The "ProperThing" prop wrench works great and allows you to use a torque wrench to torque to specs. Get one from your dealer, or maybe online? Make sure you get the correct one for your outdrive. Specs I quote below are for Bravo 3. Wedge wood as others stated (4x4 works well) to stop props from turning. For removal, unscrew the bolt in the zinc anode with a 1/2" socket. You'll see the first prop nut (rear most), remove it. slide the first prop off. There is a bushing (thrust hub) that should be on the prop shaft, or else is pressed up in your prop from the backside - remove it too if it is on the shaft. Remove the larger prop nut and front prop.

Reassembly: For the larger nut (front) , the Mercury repair manual states it should be torqued to "at least 100 Lb-Ft". The smaller nut should be torqued to "at least 60 lb-Ft" and they warn against running with loose props. Once installed, they should spin freely. If they don't, you are probably missing a bushing (thrust hub) - if you were changing props -- check in the bottom side of the other prop. Be sure to re-lubricate - the manual says to use any of these: Special Lubricant 101, 2-4-C Marine Lubricant with Teflon, or Anti Corrosion Grease. But a prop shop told me any waterproof grease is fine. Finally, replace your zinc anode and apply red Loctite to the threads of the bolt so it doesn't spin out. My manual doesn't show a spec for this bolt. I torqued to 30 lb-ft and used loctite. The dealer used loctite when they put new zincs on as well...so pretty sure this is worth doing!

Proper Installation (no pun intended) gives you peace of mind and helps ensure safety and preservation of these rather expensive stainless steel props. The tools are worth every cent and make the job easy.

Happy propping!

 

[Tail Chaser 661]

No prop is perfectly balanced. Just like tires on a car that cause vibrations at different speeds and need to have weights added for balance. What if by repositioning the outer prop, you moved the "out of balance" point of that prop to a position in relation to the inner prop, that lessened or eliminated your vibration? Could it be that the cavitation plate had nothing to do with that? Just a thought.

Tires used to be marked. That mark was supposed to be lined up with the valve stem.