Ventilation/cavitation/prop slip? Do I need the prop repaired?

[mattsmall1972]

My boat is a 2007 Sea Pro 186DC with the Mercury 150 EFI, as it came from the factory. I hit shoals the first summer I had it. The prop was slightly bent, but not enough to make me think it needed repair. It is in the same condition today.

My problem is that I have occasions when I want to accelerate from a stop or slow trolling, the engine revs up but the boat goes very slow. I discovered that, usually, going fast in reverse seems to correct the situation. I don't honestly understand what ventilation/ cavitation is, but it I think that it could be what I am experiencing. However, might this be prop slip? Might it just do this on occasion, rather than every time?

If not, could the slight damage to the prop be causing this? Thoughts are appreciated.

 

[jestor68]

Re: Ventilation/cavitation/prop slip? Do I need the prop repaired?

What sort of prop do you have? A Mercury prop? Aluminum or stainless steel?

 

[mattsmall1972]

Re: Ventilation/cavitation/prop slip? Do I need the prop repaired?

Mercury stainless steel, Vengeance model. Not sure of prop dimensions.

 

[Bondo]

Re: Ventilation/cavitation/prop slip? Do I need the prop repaired?

My boat is a 2007 Sea Pro 186DC with the Mercury 150 EFI, as it came from the factory. I hit shoals the first summer I had it. The prop was slightly bent, but not enough to make me think it needed repair. It is in the same condition today.

My problem is that I have occasions when I want to accelerate from a stop or slow trolling, the engine revs up but the boat goes very slow. I discovered that, usually, going fast in reverse seems to correct the situation. I don't honestly understand what ventilation/ cavitation is, but it I think that it could be what I am experiencing. However, might this be prop slip? Might it just do this on occasion, rather than every time?

If not, could the slight damage to the prop be causing this? Thoughts are appreciated.

Ayuh,.... Sounds like yer pickin' up a bunch of Weeds,...

Reverse clears the vegetation from the prop,...

 

[steelespike]

Re: Ventilation/cavitation/prop slip? Do I need the prop repaired?

Ayuh,.... Sounds like yer pickin' up a bunch of Weeds,...

Reverse clears the vegetation from the prop,...

The same thing occured to me.
"Ventilation" The prop gets fouled with air. Weeds are one cause,also damage to the prop, motor mounted too high, excessive up trim or severe maneuvers may trigger venting.Occasional venting is normal and can be an indication your setup is finely tuned.
Cupped props and 4 or 5 blade props resist venting.
"cavitation" you don't feel.it occurs in the low pressure areas on the back,underside, of the blades.
You may note some scaring in the paint and metal. While it can be severe on older al. props it isn't likely to affect the integrity
of the prop.It can be evidence that the prop is working very efficiently.

 

[Mi duckdown]

Re: Ventilation/cavitation/prop slip? Do I need the prop repaired?

Slightly Bent.??? You should post Pics of the prop. Slightly bent is never good.

 

[mattsmall1972]

Re: Ventilation/cavitation/prop slip? Do I need the prop repaired?

Yes, I agree that I need to post pics of the prop for evaluation.
The problem has happened in 100+ feet of water. Not likely that there are weeds occurring in the water where I am.
"Highly tuned" - would this mean that the slightly bent prop could be the ultimate cause since it's not true?