props

[chompy84]

how can I find out if the props on my boat are the correct ones?

2000 Maxum 2700 scr Bravo II

thanks

[Phillbo]

You need to determine what your WOT RPM's are and then determine if they are correct for your power plant.

[mrt214]

What engine and horsepower? Carb or EFI? Go to Maxum Customer Care

You can answer most of your Questions there.

[chompy84]

WOT i thing is 4500
engine 350 MAG MPI

[mmwjr]

Originally Posted by chompy84

WOT i thing is 4500
engine 350 MAG MPI

If you are achieving 4500 at WOT then you are propped correctly.

[chompy84]

https://www.mercurymarine.com/en/us/...or/#!/step-one
I just find this prop selector tool and called Mercury
they said I have the right ones on but if I want faster response I need different pitch
21 pitch
thanks for the response

[jparsons121]

As mentioned above prop sizing is done by matching the prop to the Wide open throttle range specified for each particular engine which is usually 4600-5000 for most 350 mags.
Reducing the pitch by 1” from where you are now would get you in the middle of this range, however, you’re so close it may not be worth it.

What are you trying to achieve?

[Mr Hemi]

I have a 2002-2500scr.
The Biggest improvement for me, was getting a 4x3 prop.

It was night and day, 1/2 the time to come on to plane, boat ran cooler.

I dont know why you could not drop down a size, you might have to watch your RPM more carefully, but the difference coming onto plane, and all around sporty handly will put a smile on your face.

MY 305 was Not a sporty cruiser with all the weight it was carring.
A boat load of people mad it very hard to handly and get on plane.

Juast ask anyone who went to a 4x3 and dropped a pitch.

[MoonRiver]

I am running a 18614A40 19P prop on my 94 2700scr. It gets on step pretty quick and planes out at 3200 rpms I typically run on step at 3500-3600 rpms at 22 kts +/-. Engines run cool and the boat handle nice. Then add a little trim and tabs to dial in the speed to rpm for best fuel burn rate.

[speedysprocket]

What do you guys think about my 3200 with 7.4s and bravo IIs? Props are about 21 pitch, and I cruise at 3500-3600 and 25-28 mph, WOT is nearly 5000 and 40 mph. Anything wrong with this or should I have them bent steeper?

[MoonRiver]

Speedy those sound like pretty numbers. Are you getting those # in Chesa Bay or off the coast?

[donald]

Originally Posted by mr hemi

i have a 2002-2500scr.
The biggest improvement for me, was getting a 4x3 prop.

It was night and day, 1/2 the time to come on to plane, boat ran cooler.

I dont know why you could not drop down a size, you might have to watch your rpm more carefully, but the difference coming onto plane, and all around sporty handly will put a smile on your face.

My 305 was not a sporty cruiser with all the weight it was carring.
A boat load of people mad it very hard to handly and get on plane.

Juast ask anyone who went to a 4x3 and dropped a pitch.

4x3?????????

[mmwjr]

Originally Posted by Mr Hemi

I have a 2002-2500scr.
The Biggest improvement for me, was getting a 4x3 prop.

It was night and day, 1/2 the time to come on to plane, boat ran cooler.

I dont know why you could not drop down a size, you might have to watch your RPM more carefully, but the difference coming onto plane, and all around sporty handly will put a smile on your face.

MY 305 was Not a sporty cruiser with all the weight it was carring.
A boat load of people mad it very hard to handly and get on plane.

Juast ask anyone who went to a 4x3 and dropped a pitch.

The OP has a Bravo 2 not a Bravo 3.

[Mr Hemi]

Thanks. Did not realize that Bravo 2 was different than my Bravo 3.

[mmwjr]

Originally Posted by Mr Hemi

Thanks. Did not realize that Bravo 2 was different than my Bravo 3.

I’m assuming you meant a 4 blade forward prop sand a 3 blade aft prop. The Bravo 2 is a single prop that can handle up to a 20” diameter.

[speedysprocket]

Originally Posted by MoonRiver

Speedy those sound like pretty numbers. Are you getting those # in Chesa Bay or off the coast?

In the Bay. Went to the light tower once, and must have had the current with me both times- did 28-29 mph the whole time, and in 1-2 foot swells

[shrew]

Originally Posted by speedysprocket

What do you guys think about my 3200 with 7.4s and bravo IIs? Props are about 21 pitch, and I cruise at 3500-3600 and 25-28 mph, WOT is nearly 5000 and 40 mph. Anything wrong with this or should I have them bent steeper?

5,000 rpm seems a little high for an engine spec'd with a max rpm range of 4400-4800.


An change of 1" of pitch should yield a change of 200 RPM difference. Increasing pitch by 1" in your case would lower you down to a bit under 4800 rpm and you really would be in the sweet spot.

Getting in the range is great, getting to the high of of the range is even better. Being outside is risky IMHO.

[shrew]

Originally Posted by chompy84

WOT i thing is 4500
engine 350 MAG MPI

Keeping the same size prop and reducing by 1" should raise the max RPM to 4700 and should have a slight improvement on time to plane. It might lower top speed, and possibly lower cruise speed at the same relative RPM.