Bravo III prop vibration

[flippen]

I noticed at the end of last season a slight prop vibration at around 3K RPM. I checked the prop and saw some very small nicks around .062 inches. Will this caue the vibration or is there a greater potential for a bent prop ?

[frodo13056]

You didn't mention if you have an aluminium or stainless prop but either way, vibration is not a good thing as something is not rotating correctly. Excessive vibration opens up a whole new can of worms when it comes to prop shaft seals, bearing wear, gear wear, etc. If you have a stainless props, you increase your chances of bending the prop shaft if you impact an object with the prop.
Pull the prop(s) and take to a prop shop to get them checked.  It could also be a bent prop shaft which can easily be checked by using a dial indicator if you happen to have one handy or you know someone that has one.

[DaleM]

You obviously bumped something as evidenced by the nicks.  Like frodo said get them checked out.  Also be sure to index them correctly when reinstalling.  Lead prop one blade straight up, rear prop one blade straight down.

[raybo3]

Hey Frodo I thought Bravo 3's only came with stainless props??????

[Black_Diamond]

Yup - Bravo III's only come with stainless props.

[flippen]

Mine only had the aluminum props when I bought it used from the dealer. So if it had them they were long gone. I checked the base of the props by rotating with a run out guage and they are ok. Probably one for the props is "tweaked".

[Babyboomer]

You didn't mention if you have an aluminium or stainless prop but either way, vibration is not a good thing as something is not rotating correctly. Excessive vibration opens up a whole new can of worms when it comes to prop shaft seals, bearing wear, gear wear, etc. If you have a stainless props, you increase your chances of bending the prop shaft if you impact an object with the prop.
Pull the prop(s) and take to a prop shop to get them checked.  It could also be a bent prop shaft which can easily be checked by using a dial indicator if you happen to have one handy or you know someone that has one.

All Bravo 3 's ar stainless

[Capt Ron]

Evey new boat I bought with a Bravo II had the props installed improperly. This will cause a slight vibration at the lower rpms. Check your alignment by putting the front prop blade at 12 o'clock, the second prop blade should be at exactly six o'clock. If they aren't, remove the second prop and slide it back on so it is at six o'clock. You would think Rinker could do this properly??? My other boat was Chaparral, same thing... This removed the vibration I was exerpiencing around the 2000 to 2500 rpms range. Like Babyboomer said, all Bravo props are stainless steel, you hit anything with them and you will be replacing your gear set. Aluminum props bend too much to use them as counter rotating.

[frodo13056]

Actually, I've seen several BIII drives with aluminium props - and obviously, as flippen stated, his boat came with aluminium props on his BIII drive so there are aluminimum props available for the BIII drives. All of the BIII drives I've seen with aluminium props were older drives. I agree that the newer BIII drives are probably stainless props.

[flippen]

OK, I am an idiot..... I assumed because of the brushed finish they were aluminum because my High Five stainless on my old boat was polished and made an assumption they all cam that way so I DO have stainless props. After boating this summer I have concluded that the props are ok because I can trim the vibration out. So I conclude tha this may be an outdrive alignment issue which I will take care of at the ned of the season.